SAN DIEGO -- Gang detectives were investigating a late-night attack in San Ysidro that sent a 16-year-old boy to the hospital with a minor stab wound, police said Friday.

The attack in the 200 block of West Park Avenue, near Sellsway Street, was reported at 9:42 p.m. Thursday, according to San Diego police Sgt. Alan Hayward.

A 16-year-old boy was walking on West Park Avenue, near Sellsway Street, when he was beaten and stabbed by four young men, Hayward said.

The boy went home and told his 19-year-old brother about the attack and they both returned to the scene to find the assailants, who then beat the first victim's brother, Hayward said.

After the second attack, the assailants yelled gang slogans as they ran away, he said, adding that San Diego police gang detectives were investigating.

The younger victim sustained a minor stab wound under his left arm, according to Hayward.