A powerful earthquake swayed buildings from Los Angeles to Tijuana, killing two people in Mexico, blacking out cities and forcing the evacuation of hospitals.

A strong earthquake south of the US-Mexico border swayed high-rise buildings in Los Angeles and San Diego and was felt across Southern California and Arizona.

Nine victims of a mid-air collision between a coastguard aircraft and a US Marine Corps helicopter were feared dead today as the investigation focused on how the crews failed to see each other in a heavily-used military training area.