Anti-war protesters urge British lawmakers to reject call for airstrikes against IS in Syria

Hundreds of demonstrators in London are urging British lawmakers not to back airstrikes on the Islamic State group in Syria.

Protesters chanting "Don't bomb Syria" gathered outside Prime Minister David Cameron's 10 Downing St. office. Protests were also being held Saturday in other British cities.

Britain's Royal Air Force is already part of a U.S.-led campaign against the militants in Iraq, and on Thursday Cameron argued that the strikes should be expanded to Syria. He said, "we have to hit these terrorists in their heartlands."

The government is trying to build support among lawmakers for military action before calling a vote in Parliament, which could come next week.

The main opposition Labour Party is deeply divided. Leader Jeremy Corbyn says he will oppose airstrikes, but many Labour legislators back them.