GENEVA (AFP) - A gunman has opened fire in a village in southern Switzerland, killing three people and wounding two others, police said on Thursday.

The man, who had reportedly been drinking heavily before the shooting and was armed with an assault rifle, launched the attack in the village of Daillon late on Wednesday.

As police rushed to the scene to stop the attack, they exchanged fire with the gunman and wounded him, police said.

"Three victims died at the scene. Two other people were wounded and hospitalised," said police in the canton of Valais, which borders Italy and France.

They did not identify the attacker and his motives were not immediately clear.

At around 8.50 pm local time, "the cantonal police headquarters was told that an individual was shooting at residents of the village," police said in a statement.

They were told that "several injured people are lying on the ground," adding that police accompanied by special units "immediately intervened and neutralised the suspect," the statement added.

The police came under threat and there was an exchange of fire, resulting in the suspect being wounded, cantonal police spokesman Jean-Marie Bornet told AFP. None of the police were hurt.