Four Royal Air Force Tornados took off from a British air base in Akrotiri, Cyprus, shortly after the 397-223 vote by lawmakers in the House of Commons.

A Ministry of Defense spokesman said the planes had conducted strikes in Syria, and details about their targets would be provided today.

He spoke on condition of anonymity because he was not authorized to give his name when discussing operations.

Opponents argued that Britain's entry into Syria's crowded airspace would make little difference, and said Cameron's military plan was based on wishful thinking that overlooked the messy reality of the Syrian civil war.

Cameron has long wanted to target IS in Syria, but had been unsure of getting majority support in the House of Commons until now.

Read more: British Parliament approves airstrikes against militant group in Syria

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