Seven police officers have been killed in an explosion and shooting attack in Colombia, BBC News reported.

They were leaving a social event in the south-western department of Huila when their vehicle hit a road mine.

They were then shot dead in the ambush, a police spokesperson said.

It is the worst attack on security forces since former guerrilla Gustavo Petro was sworn in as Colombia's first left-wing president less than a month ago.

Eight deaths were initially reported but the government later revised down the figure, to seven dead and one injured.

According to the national police and attorney general's office, three of the officers who were killed were aged 20 or younger.

Petro condemned the attack, calling it "a clear act of sabotage against peace" in a tweet.

Late on Friday he traveled to the regional capital of Neiva for a security meeting.

No group has said it was behind the attack, but Colombia's Blu Radio pointed the finger at guerrilla groups operating in the area.

And security sources have said that dissidents from the now disbanded communist guerrilla group, Farc operate in the area, according to Reuters.