Four people have been killed, including a six-month-old baby and a police officer, after a drunken gunman opened fire at a traveller camp in France, authorities say.

The three civilians who died were all members of the same family.

The gendarme service was alerted after shots were fired at a Roma camp in the northern town of Roye.

A spokesman for the service said the gunman opened fire on the officers when they arrived at the camp.

One of them died of his injuries while another was also hurt.

A three-year-old child was seriously wounded by the suspect before the alleged attacker was shot and injured by police.

The suspect, who is reportedly a member of the same travelling community, was then arrested.

Three bodies were found among members of the camp.

The circumstances and motive for the killings have not yet been established, police sources said.