Gunmen opened fire at a birthday party in northern Puerto Rico and killed three people including a 4-year-old boy, police said Tuesday.

The shooting injured two other children, ages 9 and 10, in the attack Monday night at a public housing complex in the U.S. territory's coastal town of Cataño, police said in a statement.

Police said two men were killed at the party and that the 4-year-old boy died at a hospital on Tuesday.

PUERTO RICAN MAN SENTENCED FOR COMMITTING HATE CRIME AGAINST TRANSGENDER WOMAN

San Juan skyline

An aerial view of San Juan, Puerto Rico, is pictured above. A four-year-old boy and two men were killed at a Puerto Rican birthday party on Tuesday. (Getty Images)

Officials said the boy was not related to the men, adding that they believe the shooting was tied to drug trafficking.

CLICK HERE TO GET THE FOX NEWS APP

No one has been arrested.