Bogota explosion: Many injured in blast near bullring
Dozens of people have been injured in an explosion in the Colombian capital Bogota, the mayor's office has said.
The explosion happened near the bullring, where animal rights activists were preparing to hold a march.
Bogota authorities said at least 40 people were injured, including 28 men and 12 women. Many are believed to be officers deployed ahead of the protest.
It is unclear if the blast was linked to the protests, which began after the city reinstated bullfighting this year.
Gareth Lewis, a British traveller staying in a hostel in La Macarena, on the corner where the explosion took place, told the BBC: "I was sitting in my room in the hostel, the windows just came in, there was glass everywhere.
"Quite a few police have been hurt, they're now sweeping up. They used tear gas and there's quite a bit of blood."
Mr Lewis, who has been advised to stay inside the hostel by officers, said he had witnessed protests "all week" and that "armed police have been everywhere".
The protests began after a decision by the constitutional court, which ruled bullfighting was part of the country's heritage and therefore could be reinstated.
The move angered animal rights activists, who have clashed with police during protests against the reopening.
In January, demonstrators were arrested and officers fired tear gas to control groups physically attacking spectators.
But the explosion was not necessarily linked to the protests.
Jorge Restrepo, director of Colombia's Conflict Analysis Resource Center (Cerac), said the attack may have been targeting the police, taking advantage of the fact that many officers were gathered together due to the bullfight.
He told the BBC it was possibly linked to a series of attacks against security forces in the capital that have taken place in recent months.
Meanwhile, Bogota mayor Enrique Penalosa, who attended the scene, has announced he was convening a security council meeting for Sunday afternoon.
"The terrorists won't intimidate us," Mr Penalosa said on Twitter. "We are going to do all that's necessary to capture them."
He earlier tweeted one police officer had been killed, but has since removed the post. It has now been reported there were no fatalities.
Two of the injured were said to be in a serious condition.