Britain announced on Saturday night that it was deploying aircraft to assist French military operations against Islamist rebels in Mali as an escalation in hostilities was claimed to have killed more than 120 people.

David Cameron's offer to transport foreign troops and equipment involved Britain in a fresh conflict that could provoke terrorist reprisals against European targets. President Fran├žois Hollande yesterday placed France on high alert as French planes bombarded targets in Mali.

Downing Street said two transport planes would be dispatched, but British troops would not join the French military mission to help recapture the north of Mali from al-Qaida-linked rebels acting against the country's government.