LONDON - Police found martyrdom videos and bomb-making components during the investigation of the alleged plot to blow up U.S.-bound jetliners, prosecutors said Monday in announcing 11 people had been charged with terrorism offenses.

Officials confirmed for the first time that the plot involved the manufacture of explosives, which were to be used to assemble and detonate bombs inside as many as 10 airliners. U.S. officials previously had said the plot appeared to involve mixing liquid-based chemicals to make explosives aboard the aircrafts.

One woman was released from custody Monday and police continued to interrogate 11 others who remain “under active investigation,” lead prosecutor Susan Hemming said.

Those charged were scheduled to appear in court today, but because of the seriousness of the accusations, it was unlikely bail would be granted.