Spanish police arrested three suspected al Qaeda operatives Wednesday out of fear they planned an airborne attack in Europe, according to Spain's interior minister, Jorge Fernandez Diaz.
While local authorities have arrested dozens of alleged militants since 2004, when a key Madrid train station was attacked, Spanish media reported these were the first caught with explosives, meaning they had become an operational cell.
The three suspects -- two from ex-Soviet republics and a Turk -- had timers and enough explosives to blow up a bus, Diaz said in a press conference in Madrid. Police believe at least two of those arrested had practiced flying small "ultralight" airplanes or using small drones, Diaz said.
Diaz called one of those arrested a "very important member" of al Qaeda who is an expert in explosives and poison.
"This is one of the biggest investigations which has been carried out up until now against the Al Qaeda terrorist group at an international level," Diaz said. "There is a clear indication that those arrested could have been planning an attack in Spain or in Europe,"
Diaz described the two suspects from ex-Soviet republics -- believed to be Chechen -- as al Qaeda members and said they were arrested as they traveled on a bus, possibly to cross into France.
"Police moved to arrest them when it became known that they planned to leave Spain," he said.
Diaz said the suspect from Turkey, who he described as a facilitator, was arrested in a house in the southern Spanish town of La Linea, where the explosives were found.
Diaz said non-Spanish, international investigations aided in the operation.