Helsinki: All five people on board two helicopters were killed Saturday when the aircraft collided mid-air in Finland and crashed to the ground, police said.

"Five people died in a helicopter accident near Eura Airport on Saturday," Detective Chief Inspector Johannes Siirila said in a statement.

According to their flight plans, one was carrying two people and the other three. They had taken off from the Estonian capital Tallinn and were bound for Piikajarvi, a few kilometres from where they came down.

According to reports, the victims included two prominent Estonian businessmen — Oleg Sõnajalg, 58, a pioneer in wind energy, and Priit Jaagant, 52, a senior business executive.

Finnish newspaper Iltalehti quoted one witness, Antti Marjanen, who reported seeing one of the helicopters hit the other during a manoeuvre.

"One of them dropped like a stone and the other one more slowly. I didn't hear any sound," Marjanen was quoted as saying.

(with inputs from AP)