AIR strikes against Libyan Islamist militants that US officials had said were staged by Egypt and the United Arab Emirates could mark an escalation of a regional struggle over the future of the Arab world.

Arab responsibility for the attacks would add to a picture of the West's regional allies acting increasingly independently in the absence of decisive US involvement, seeking security goals with which Washington might not agree.

Egypt has denied involvement in the attacks on targets in its western neighbour and sensitivity over the strikes led to confusing statements from the administration in Washington.

The US and its European partners Britain, Germany, Italy and France have urged outsiders not to interfere in Libya, which is suffering its worst violence since the overthrow of Muammar Gaddafi in 2011. The jets had attacked targets in Tripoli over the weekend.