Salvadoran President Salvador Sánchez Cerén says street gangs are attacking police to try to force his successor to negotiate with them.

President-elect Nayib Bukele is scheduled to take office June 1, and Sánchez Cerén said Tuesday that the gangs "are using threat to blackmail the incoming government to negotiate with them."

On Monday, a street gang put a fake body in an abandoned car to lure police officers into a car-bomb attack that wounded two policemen. Over the weekend, suspected gang members killed two off-duty police and three soldiers.

National police director Howard Cotto says the attacks were the work of the Mara Salvatrucha gang, known as MS-13.

In 2012, the government of a previous president negotiated a truce with gangs that included giving gang leaders greater liberty in prison.