BOGOTÁ, Colombia — A wave of bombings carried out against police stations this weekend has rocked Colombia’s Caribbean coast, with three attacks within 24 hours killing seven officers and wounding dozens more.

The violence began in the early morning hours Saturday when two people on a motorcycle threw an explosive device into a police station in Barranquilla, a major port city gearing up for its annual carnival celebration in two weeks. Five police officers were killed in that attack, and at least 40 injured.

A second strike, in Santa Rosa del Sur, a rural area in the state of Bolívar, killed two officers and wounded a third shortly before midnight Saturday, according to a police statement.

Then, early on Sunday morning, the Barranquilla police were hit with another bomb, this one at a small police station, which wounded four officers and three civilians. The police said the bomb had been left outside the station, but witnesses told El Heraldo, a local newspaper, that it had been tossed from a passing taxi.