One person was killed and four others wounded when armed men burst into the home of a union official in the southwestern city of Cali and started shooting, Colombian authorities said Thursday.

While the target of the attack, municipal workers union Vice President Adolfo Devia Paz, was not hurt, his brother was killed.

The brother's wife and 3-year-old child were wounded, Cali police chief Fabio Castañeda said.

Also hurt was Adolfo Devia's police bodyguard, who managed to wound one of the attackers.

Investigators have yet to determine the motive of the shooters, according to Castañeda, but union President Alvaro Velasco told reporters that Devia and other union officials have received death threats.

More than 2,800 union members have been slain in Colombia since 1986, making the Andean nation the world's most dangerous country for labor activists. EFE