Psatha, Attica, Greece: Two firefighting helicopters collided mid-air while battling a major wildfire near Psatha in Greece's Attica region on Sunday, resulting in the deaths of two crew members.

According to authorities, the helicopters were conducting a water-dropping operation to help contain a massive wildfire that has destroyed more than 100 homes northwest of Athens and scorched thousands of hectares of land.

The victims have been identified as one Greek national and one Danish national, while two other crew members survived the crash.

Videos circulating on social media appear to show the two helicopters approaching each other at low altitude before the collision. Preliminary visuals suggest that the main rotor of the lower helicopter struck the underside of the helicopter flying above it during the operation. The lower aircraft crashed and burst into flames, while the second helicopter released its water load and managed to fly away.

The exact cause of the collision has not yet been officially confirmed. Greek authorities have launched an investigation to determine the circumstances that led to the accident.

The incident comes as Greece continues to battle an intense wildfire emergency, with firefighters and aerial crews working around the clock to contain multiple blazes fueled by hot, dry, and windy conditions across the country.