London ? Three British Muslims were convicted Monday of plotting to murder thousands by downing at least seven trans-Atlantic airliners in simultaneous attacks designed by al-Qaida to be the deadliest terrorist strike since Sept. 11, 2001.

Abdulla Ahmed Ali, 28, Assad Sarwar, 29, and Tanvir Hussain, 28 were found guilty at Woolwich Crown Court in London of leading a plan to detonate bombs on aircraft bound for the United States and Canada, using liquid explosives hidden in soda bottles.

Four other men were acquitted of conspiring to bomb airliners, but admitted lesser charges — and in one case conspiracy to murder. An eighth man was cleared completely.

The case brought sweeping new restrictions for air passengers, including limits on the amount of liquids and gels they can take carry on board.

British and U.S. security officials said the plan was directly linked to al-Qaida and guided by senior Islamic militants in Pakistan.

Authorities estimate that, if successful, about 2,000 passengers would have died. Had the bombs been detonated over U.S. and Canadian cities, hundreds more would have been killed on the ground.

Prosecutors said the suspects had identified as targets seven flights from London’s Heathrow airport to New York, Washington, San Francisco, Toronto, Montreal and two to Chicago.