LONDON: Britain called for restraint on Wednesday after Israel killed Hamas military chief Ahmed Jaabari in Gaza, saying that further violence was in no one's interests.

"We are aware of reports of the death of the senior Hamas commander Ahmed Jaabari," the Foreign Office said in a message posted on Twitter.

"We continue to call on all sides to exercise restraint to prevent a dangerous escalation that would be in no one's interests."

British Foreign Secretary William had warned at an EU-Arab League meeting in Cairo on Tuesday that the world was "in danger of sleep walking into a serious crisis" if there was no progress on the stalled Middle East peace process.

Jaabari was killed and his bodyguard wounded in an air strike on their car in Gaza City on Wednesday.

The Israeli military said his death marked the start of a military operation against armed groups in Gaza. Hamas' military wing vowed to retaliate, warning that the killing had "opened the gates of Hell."