Transcript for Airports Bump Up Security Procedures
You can. -- boards on high alert today a threat of an undetectable bomb from across the pond. As we head into this Independence Day holiday right now the international hot spot the united. And Michelle Franzen in New York. US officials are warning governments overseas to be even more cautious in their airport security. Because of bombs that may not be detectable with normal screening methods. Now all direct flights coming from the UK into the US receding extra scrutiny the BBC security correspondent frank Gardner has the -- He's -- this morning a new -- would signs of anything unusual. But -- the government has announced that new unspecified security measures are being put in place the transatlantic flights to America. It's in response to the belief that al-Qaeda operatives in Syria a planning to smuggle sophisticated bombs on to planes. I appreciate greatly the cooperation between the United States government and the government here in the UK. We have to remain vigilant unfortunately I wish we lived in a world where we didn't face ongoing threats and where. Those who would death wish to do us harm didn't have increasing. Access to technology and new ways of trying to inflict. Violence. The threat originates with his group Al -- in Yemen. The more than five years -- they've been devising hard to detect bombs that have successfully updated airport security and three times. Only one device went off on the ground killing the man who carried it. In 2009 the circle -- Obama failed to detonate his bomb over Detroit and is now in prison. But in 2010 bombs hidden in these -- would have worked if an intelligence tip off -- -- -- police to find them but east midlands airport. This is the man designing the bombs aside. A whole new generation of high tech -- This exquisite sex but showed -- the effect if you can just a small drop of liquid explosives. When you can't detect explosives one of the that the traditional ways of doing just by sniffing to use an electronic -- you could use a -- -- paper explosive. -- vapor pressure extras if there's one that doesn't really give off any vapors of there's nothing to sniff and that's what makes them. -- deal for smuggling through a security and make some hard to -- -- -- the fighting in Syria pulling in thousands of jihadist from Europe. Intelligence analysts worried that some of them are being partly trained to get back -- and -- attacks. Both US and British airports already have extensive security measures. Including explosives detectors and body scanners that it's not clear what more proportions can be taken. The passengers are being warned to expect delays for the sake of a safer flight. -- -- -- -- And we are joined now by Chris -- security editor at Jane's aviation from Manchester in the UK. Just an idea UK officials are not commenting on the di tale of the security changes do we know how officials. Are looking for -- what they describe as a new type of bomb. Well we're looking at a range of technology isn't techniques really. I'm not sure of this is on the scene on -- -- -- -- -- -- couldn't imagine for example. Trace of -- Apollo school detection. It's the the gates before you get on board planes. It's the central securities -- as well. Examining passenger baggage to determine whether. It has been tampered with whether it may contain something. Such this. An explosive. That -- home soon passengers on board flights. And didn't do we know who they are focused seen their information how they're based they're there information are they focusing on citizens from the western nations as they -- travel on the ice. Liked. What I think we're focusing on anybody that's troubling to the united states -- the coming days. I'm not just from the UK bit of pools across Europe. About Apple's across the Middle East. And indeed Africa. The threats. -- -- perceived. -- seems to be quite wide ranging. Only affecting those direct flights the non stop flights into. The United States. So -- the focus of everyone's attention of months. The idea being done to stop any would be a Tonka. From getting on the plane school. And -- we've heard about this new type of bomb making for the last few weeks but is -- coincidence or not but the threat. Is coming just as we head into a holiday here in the US. Well -- indeed you are heading mutants to a holiday to let the Independence Day. Celebrations upcoming. There is no coincidence of course of this warning. Comes had -- it's time. I'm truly does peak travel time in the United States. The US government's -- wanting to keep. Its own citizens the citizens of other countries as well who might be traveling into the US. Over this coming weekend. -- -- -- -- the said no coincidence that. Built the types of mantra is that we -- talking about a potential. New device having been develops or in the process being developed. Sounds that is giving people calls -- concern a moment some polls biko's. Anytime you -- about al-Qaeda in the Arabian Peninsula. Qaeda in Yemen being involved. Well they -- prior history in developing these types of weapons. And give us an idea you mentioned those two terrorist groups could have an idea what their tactics have been in the past and how they may have been. -- in those skills in the previous years. Al-Qaeda in the Arabian Peninsula particularly. -- -- track record and developing. Weaponry that cannot -- Poor security and I think Barack sued the 2009. Under way Obama incidents the device that it's Abu Musab -- was carrying on his listen. Happens to be developed by -- him a series the -- to bomb -- involved with a Q&A MP. The fights that HUAP. Is now allied with. -- those reforms and it's been Syria gives rise -- concern that. Some of these weapons might well be filtering into Syria. Across the Turkish border and into Europe. And you know Chris we've seen a lot of concern about homegrown terror UK citizens going to fight overseas in Iraq and Syria and then coming back to Britain. Certainly we're also here in -- a little bit here in the US with the recent arrest. Some idea of what the concerns are what is there a profile anymore that security officials can can look to. There isn't a pro finalists such -- there is a high degree of concern. Led -- many of those who being going ounce to Syria from the United Kingdom particularly. Two fights. On behalf of the the various groups -- off pointing -- Syria. Might well become. In -- -- it if you -- -- -- the -- the thinking the way -- move those terror groups on -- indoctrination. Well obviously filtered back into the United Kingdom when they do -- say. The police -- -- taking a proactive with the stones yeah. By. Capturing season holds thing. Those people as they come back and into -- very carefully. -- jailing them in some instances. To and so forth. But she knew there are several hundreds. These people that are in the wild Oltmanns it didn't -- won't -- to come back and -- to parents can track possibly. On aviation. And certainly some recent warnings -- their prime minister David Cameron was very dire when speaking about this in June here is what he had to say. Will be making sure there -- security intelligence and policing resources are focused. Particularly on this half of the world in the danger of British people traveling that becoming radicalized and returning to the UK. Do you think it's likely that a possible attack like this. Would be perpetual perpetuated by these radicalize meant. It is possible Nam. Whether it's likely as an entirely different question of course but it is possible that somebody who has become radicalized in the a in the Middle -- in Syria particularly. Comes back into UK and -- -- an atrocity in the tank. The outs always the possibility into the upper low -- they the minds of the security services in the united could memorable moments. And will be -- some considerable time to come on the suspect. And Chris just one last question we don't have a lot of details about what these possible new bomb making techniques are or do we have any idea of how they could be concealed are there any sort of theories out there. No we sing and pollster cools the deed the underway Obama. Well you have the device hidden and -- under -- A device so which was particularly tricky too good to -- because. He didn't contain a conventional. Detonating. Device. An electric decimate said it was Susan chemicals which -- Pumped into the explosive to ignites it but unfortunately for abdomen time he was -- -- before he grounds. The ability to -- to track him full. In respect -- prince cartridge bombs. They were concealed and -- the printer cartridges very carefully. They groups whose -- They were for all intents and -- genuine printer cartridges. Only when close inspection was given to them did they reveal themselves those as. Explosive devices and -- -- was devices -- -- So a variety of techniques that are being used of the moment. And it's up to security on the security companies these security vendors they. To develop technology is. Which are capable of detecting such a wide range of potential threat. Chris -- security editor at Jane's aviation thank you for joining us today. You can keep up with the story in real time by downloading the ABC news -- -- starring this story for exclusive updates on the go. Even watch an international hot spot I'm Michelle Franzen in New York.
This transcript has been automatically generated and may not be 100% accurate.