Updated

Police say four people have been killed and one injured after an ex-policeman opened fire on his wife's family in Montenegro.

The slayings happened late Monday in the northern town of Andrijevica when a man burst into a family house and, after a short argument, gunned down his father-in-law, mother-in-law and elder brother-in-law. A younger brother was injured.

Police say the attacker tried to escape, but when confronted by a police patrol, he committed suicide by activating a hand grenade.

Police gave no information on possible motives for the killings.

Local media say the wife of the suspected killer committed suicide last year, leaving their two minor children behind.