Zagreb, Nov 24 (IANS) One person was killed and four others injured in a hand grenade explosion in an apartment building in the southern Croatian city of Knin on Saturday night, local police said in a statement on Sunday.

A 25-year-old young man lost his life in the explosion, while two of his friends, aged 23 and 25, and two girls, one of whom is 21 and the other a minor, suffered serious injuries and were hospitalized, the statement said.

The police investigation found that the injured 25-year-old man brought an M75 hand grenade and handed it over to another 25-year-old during a party in the apartment building.

Due to unprofessional handling, the grenade was accidentally activated by the man who was killed at the scene. The conditions of the four injured were serious but stable, the statement said, Xinhua news agency reported.

Since the beginning of this year, the Police Department of Sibenik-Knin has launched a campaign called "Less arms, fewer tragedies" and urged citizens to voluntarily surrender weapons and mine explosive devices left over during the 1991-1995 Croatian War of Independence.