Officials say at least three police officers were killed and another 14 injured when a homemade bomb exploded outside a police station in the Colombian city of Barranquilla.

The head of Barranquilla's police says Saturday's attack may have been in retaliation for the arrest of a local crime boss known as "Happy," who had been extorting businesses and overseeing the sale of drugs in the Caribbean city.

Mayor Alejandro Char says one suspect has been arrested and two more identified. Authorities are offering an $18,000 reward for information on those responsible for the attack.

The explosion took place shortly after 6 a.m. as police were lining up in formation in the police station's patio following a shift change.