Spanish officials confirmed Thursday (August 2nd) that police arrested three suspected al-Qaeda members and seized explosive materials, AFP reported.

Interior Minister Jorge Fernandez Diaz said during a news conference that one of the suspects was "a very important operative in al-Qaeda's international structure".

On Wednesday, police arrested two of the men as they were travelling on a bus from Cadiz to Irun near the French border.

The third suspect, whom Diaz described as a Turkish national and an al-Qaeda logistics expert, was also arrested Wednesday in La Linea de Concepcion in southern Andalucia province. Police discovered explosives and documents related to flying light aircraft at the time of the arrest.

"This is one of the biggest investigations conducted until now against the al-Qaeda terrorist group on an international level," Diaz said, adding that police had the men under surveillance.

The suspects are "extremely dangerous people", he said, adding that foreign intelligence services informed officials in Spain that one of the suspects "has extensive experience in the manufacture of poison and car bombs".