Greek firefighting helicopters in mid-air collision, four crew missing

Al Jazeera:

A search-and-rescue operation for four pilots is underway in Greece after a mid-air collision between two firefighting helicopters.

Television video showed one of the helicopters explode and plunge to the ground in flames after an apparent rotor collision. They were in the Psatha area near Athens battling wildfires that have destroyed more than a hundred homes and forced evacuations across Greece.

Firefighters were battling to contain a separate blaze around Porto Germeno on the Gulf of Corinth, where flames crossed a mountain and reached a military firing range, activating unexploded ammunition.

Nearly 500 firefighters have been deployed with reinforcements also arriving from France and Romania.