Man, 21, Is Arrested in Connection With 2 Drive-By Shootings : Van Nuys: Orlando Ulloa is suspected of being the driver and possibly the gunman in the attacks that left a 15-year-old boy dead and four people wounded.

A 21-year-old man was arrested Sunday in connection with two drive-by shootings that left a 15-year-old boy dead and four people wounded--including a 9-year-old boy, Los Angeles police said.

Orlando Ulloa, 21, is suspected of being the driver and perhaps the gunman in the two shootings, which took place within 90 minutes of each other Saturday night in a Van Nuys neighborhood where gang tensions have run high since an April 14 shooting left two dead and two wounded.

Saturday’s first shooting occurred about 7 p.m. at the Valerio Gardens housing project. Three people were shot and wounded when an occupant opened fire from a black Toyota Supra, Detective Lee Jett said.

The victims were identified as Florencio Alvarado, 28; Diang Dongdy, 40, and a 9-year-old boy whose name police would not release. The boy was shot in the back, said Regina Birdswell, spokeswoman for Children’s Hospital in Los Angeles, where the child is expected to recover.

“The bullet is lodged in the abdominal cavity, but they are going to leave it in,” Birdswell said, explaining that if a bullet is not doing any damage, doctors often elect to leave it rather than put a patient through the trauma of surgery. “There are a lot of people walking around in that same situation.”

Alvarado was in critical condition at Northridge Hospital Medical Center, and Dongdy was in serious condition at Holy Cross Medical Center in Mission Hills, police said.

About 90 minutes after the first attack, occupants of a car similar to the one in the first shooting opened fire at the corner of Sherman Way and Hazeltine Avenue, killing 15-year-old Jaime Tlatenchi and wounding his 17-year-old brother.

Police said both youths were suspected gang members.

“They were sitting at the bus bench, and the car drove up and the passenger opened fire,” Jett said.

In addition to Ulloa, who was booked for investigation of murder and was being held without bail at the Van Nuys Division Jail, police said they were searching Sunday for other suspects in the shootings.

About six weeks ago, a gang dispute in the same neighborhood left two dead and two wounded, and police were investigating Sunday whether Saturday’s shootings were connected to the earlier attack.

“I’m hoping [the latest shootings] weren’t repercussions,” said Blinky Rodriguez, a Van Nuys activist who helped arrange a truce among San Fernando Valley gangs, which has been in effect for 19 months.

In an unrelated incident Saturday, a 23-year-old man was killed and a teen-age boy was wounded in what appeared to be a gang-related shooting in Pacoima. Jose Gonzalez Diaz of Pacoima was pronounced dead at the scene and the teen-ager was taken to Holy Cross Medical Center where he is expected to recover, police said.

Asked whether he thought the truce was still in effect, Jett said: “Well, it makes you wonder, if you know what I mean. Things are really heating up.”