Six men, including a former U.S. military explosives specialist, were convicted Wednesday of having plotted to black out London and most of southeastern England in a series of bombings of electrical power stations by the Irish Republican Army a year ago.

The six, some of whom were described by prosecutors as senior commanders of the IRA, were found guilty of conspiracy to cause explosions and sentenced to 35 years in prison each. Two men, one charged with being a courier and the other accused of providing premises and false papers to the conspirators, were acquitted.

The group was picked up in coordinated raids on three rented London hideouts last July 15.