A van packed with more than two dozen people crashed on a highway in the Southern California desert, killing at least two suspected illegal immigrants and critically injuring several others, officials said.

The crash on westbound Interstate 8 occurred after 10 p.m. Monday when the van, followed by U.S. Border Patrol officers, suddenly swerved into the center divider at up to 65 mph and rolled over several times, said Officer Robert Gonzales, a California Highway Patrol spokesman.

"For unknown reasons as of now, the van swerved," Gonzales said.

The incident began when authorities got a call that numerous people were climbing into a white van on the side of the highway, Gonzales said. The highway patrol relayed the call to the Border Patrol, which sent agents to the area near the U.S.-Mexican border, about 120 miles east of San Diego, he said.

At least 27 people were inside the van but none were children, Gonzales said. Several were ejected from the vehicle. The driver escaped and fled on foot but Border Patrol officers later caught him.

Two men, aged 28 and 32, died at the scene, said Charlie Lucas, supervising deputy coroner for the Imperial County Sheriff's Department. They carried Mexican identification, he said.

Thirteen of the injured were taken to El Centro Regional Medical Center, said charge nurse Erica Rodriguez. Three who were in critical condition were being sent to the University of California San Diego Medical Center, she said.

Eleven other passengers were taken to Pioneer Memorial Hospital, said Summer Winford, the hospital's house supervisor. One was in critical condition, she said.

The crash came only hours after President George W. Bush said he would order as many as 6,000 National Guard troops to secure the U.S. border with Mexico and urged U.D. lawmakers to give millions of illegal immigrants a chance at citizenship.