Several people have died after two helicopters collided mid-air in Finland, police said Saturday.

A total of five people were on board the two aircraft, which crashed to the ground after the collision over Eura, western Finland.

"The accident has resulted in several fatalities. The exact number of victims and the identities of the passengers are still being determined," police said.

Finnish police confirmed that three people were traveling in one of the aircraft and two in the other.

The civilian helicopters had taken off from the Estonian capital Tallinn, and were heading towards Piikajarvi Airport in Kokemaki, about 15 kilometers (9 miles) from Eura airport. 

Media reports said they were carrying Estonian businessmen.

Finnish and Estonian authorities were cooperating closely, a police statement said.

Police have sealed off the area near the accident as preliminary investigations were underway. Roads leading to Eura airport have been closed.

"Several rescue units and police patrols" were at the scene, said police, who were alerted to the crash at 12:35 p.m. local time (10:35 a.m. GMT)

The two helicopters involved in the collision were found approximately 100 meters apart in a wooded area near Eura airport.

It was not immediately clear what caused the collision.

Finnish newspaper Iltalehti quoted a witness who said they had seen the helicopters collide during a manoeuvre.

Edited by: Rana Taha