A British police commissioner has revealed that a large Islamic terror attack was planned for London, but was thwarted.

Earlier Sunday, Metropolitan Police Commissioner John Stevens said London’s police have “thwarted a number of attacks.”

“There’s a large number of people going through the courts,” he told BBC TV. “We can’t talk about the details of that, which is slightly frustrating. But we have had considerable successes and that’s been the result of working extremely hard with the intelligence services.”

Discussing the cases of alleged terrorists in detail could compromise any future trial, Stevens has said previously.

Five days after the March 11 train bombings in Madrid, Stevens said a terrorist attack in Britain was “inevitable.” On Sunday, he said the terrorist threat remained “real.”

“When I said attacks were inevitable, during that period of time there was an attack taking place on London. But we are there to ensure that that attack does not take place, and thank God up to date we have been successful,” he said.

He didn’t give details of the planned attack. However, in late March police arrested six men and seized 1,300 pounds of potential bomb-making fertilizer. The men have been charged with conspiring to cause an explosion and their trial is tentatively set for September 2005.