The attacker jumped into the arena and fired before fleeing, police chief Jose Humberto Henao told Efe news agency.

Local reports say the audience of about 20 people, mostly children, thought the shooting was part of the show before realising both men had been killed.

Last year, a prominent circus clown, known as Pepe, was also shot dead by a unknown assailant in Cucuta.

The motive for the latest killing remains unclear, police said. Local media reports suggest two attackers may have been involved.

One clown was shot in the head as he performed on stage, about an hour into the Circo del Sol's evening show.

The second, named as 18-year-old Franklin Leal, from Cucuta, was then shot as he stood by the ticket booth, according to the newspaper La Opinion.

The travelling circus had set up in a suburb of Cucuta, capital of Norte de Santander province near the Venezuelan border, about 10 days earlier, the paper says.