A previously unknown hackers' group calling themselves "The Unknowns" has compromised websites and obtained documents from NASA, the U.S. Air Force, the French Ministry of Defense, the European Space Agency, the Bahrain Ministry of Defense, the Thai Royal Navy and Harvard University's School of Public Health.

The group posted several screenshots and documents on Pastebin.com, showing the results of its intrusions: http://pastebin.com/uhWSRrSf

A website that was breached at NASA's Glenn Research Center shows a screen from the Interagency Advanced Power Group which conducts research on space and land-based energy programs with the Army, Air Force, Navy, Energy Department and NASA.

"Victims, we have released some of your documents and data," the group wrote on a web posting. "We probably harmed you a bit but that's not really our goal because if it was then all of your websites would be completely defaced but we know that within a week or two, the vulnerabilities [sic] we found will be patched and that's what we're actually looking for. We're ready to give you full info on how we penetrated threw your databases and we're ready to do this any time so just contact us, we will be looking forward for this."

A NASA spokesman, contacted by ABC News, said, "NASA security officials detected an intrusion into the site on April 20 and took it offline. The agency takes the issue of IT security very seriously and at no point was sensitive or controlled information compromised. NASA has made significant progress to better protect the agency's IT systems and is in the process of mitigating any remaining vulnerabilities that could allow intrusions in the future."

A member of the group who uses the Twitter handle ZyklonB also claims to have penetrated computer systems at Oak Ridge National Laboratory. A spokesman for the laboratory said, "The laboratory network was never compromised."

The spokesman said that ZyklonB gained access to an external website where scientists make data publicly available for research purposes.  It is unclear if the group was trying to gain access to the lab's more sensitive networks.

"We are a new hacker group, we have never been in any hacking team before," the group said in a message posted Friday. "We are not Anonymous Version 2 and we are not against the US Government. We can't call ourselves White Hat Hackers but we're not Black Hat Hackers either… Now, we decided to hack these sites for a reason…These Websites are important, we understand that we harmed the victims and we're sorry for that - we're soon going to email them all the information they need to know about the penetrations we did."

"And for all the other websites out there: We're coming, please, get ready, protect your website and stop us from hacking it, whoever you are. Contact us before we take action and we will help you."

The group posted information from the Air Force Auxiliary's Civil Air Patrol.

Capt. Chris Sukach a spokesperson for the Air Force Space Command, said in a statement that his group is investigating.  "For obvious security reasons, we generally do not discuss specific vulnerabilities, threats, or responses to them.  The Air Force will continue to monitor the situation and, as always, take appropriate action as necessary to protect Air Force networks and information."

The group also claimed it compromised a research database connected to Harvard's School of Public Health and the Dana Farber Cancer Center. An official briefed on the matter said that no patient data was on the server that was breached. It is unclear what information was compromised from the Harvard system.

Officials with the FBI declined to comment if they are investigating the computer breaches.