A court in the United Kingdom Tuesday found two Islamic extremists guilty of plotting an attack on the Jewish community, which Manchester police say would have been “catastrophic.” 

Walid Saadaoui, 38, and Amar Hussein, 52, according to Sky News, had purchased weapons they planned to use in a suicide attack on Jews. An undercover officer said that Saadaoui had told him that he would target schools and gatherings, with the goal of killing “young, old, women, elderly, the whole lot, killing them all.” Christians would also be targeted.

The prosecution told the Preston Crown Court that Saadaoui wanted to replicate the 2015 Paris attacks that killed 130 people.

Saadaoui was caught during an undercover sting operation during which he tried to take possession of weapons he’d purchased for the attack. 

Greater Manchester Police Assistant Chief Constable Rob Potts told Sky News that if the plan had been successful, it would have resulted in "the deadliest terrorist attack in U.K. history.” 

The attack was intended to be revenge for Israeli attacks on Gaza.