A DRUNKEN Colombian soldier threw a grenade into a small town street party and killed a seven-year-old boy and four other people overnight, military and civilian authorities said.

The soldier went absent without leave from his base in the southwestern province of Huila and got drunk in the town of El Jardin before detonating the grenade, said an official at the nearby municipality of San Jose de Isnos.

Five people were killed and eight injured in the incident, the official said.

The army arrested the soldier and began a criminal investigation under military law, an army spokesman said.