A ray gun that shoots a beam which makes people feel as if they will catch fire has been unveiled by the US military.

A joint US-Iraqi offensive has killed some 50 insurgents so far in battles that raged today around a blistering hot frontier town in the American military’s latest campaign to stop foreign fighters from pouring through neighbouring Syria.

US forces launched airstrikes against suspected militant bases in Fallujah and carried out probing attacks on the city’s outskirts, as they prepared for a major operation in the insurgent bastion that has become the symbol of Iraqi resistance.