LONDON, March 22 (IslamOnline.net & News Agencies) - Four U.S. soldiers were killed when their two Humvee vehicles came under attack in central Iraq, Sky News television reported Saturday, March 22, citing one of its reporters with U.S. forces.

It said the soldiers, from the first brigade of the 3rd Infantry Division, were on a reconnaissance mission when their vehicles were hit by rocket-propelled grenades.

The attack was followed by a "coordinated mortar attack," Sky quoted its correspondent Colin Brazier as saying. The exact location of the incident was not given.

The deaths brought to some 24 casualties - British and U.S. - so far from the Anglo-American campaign to invade and occupy Iraq, on its third day.

Earlier, two helicopters from Britain's Royal Navy collided in mid-air today over international waters in the Gulf and seven crewmen on board are confirmed dead, a British military spokesman said.

The incident occurred at around 4:30 am local time (0130 GMT) and involved two Royal Navy Sea King Airborne Early Warning helicopters, Agence France Presse (AFP) quoted the spokesman as saying.

All seven crewmen aboard the two British helicopters are dead, a British military spokesman said here.

This accident comes only a day after eight British Royal Marines and four U.S. airmen were killed in a helicopter crash in Kuwait .