U.S. authorities closed the world's busiest land border crossing on Tuesday after a shootout between suspected Mexican human traffickers and U.S. agents, U.S. officials said, Reuters reported.
"The port is closed and will remain closed for several hours," U.S. Customs and Border Patrol spokeswoman Angelica Decima said after the incident at the congested San Ysidro crossing between the Mexican city of Tijuana and San Diego.
The suspected smugglers shot across busy lines of traffic at U.S. agents when they tried to stop three vans packed with about 70 illegal immigrants from crossing into the United States, the officials said.
The agents returned fire, and three people in the vans and a motorist were wounded, said Lauren Mack, a spokeswoman for U.S. Immigration and Customs Enforcement.
Mexico's violent drug gangs are increasingly moving into the lucrative people-smuggling business, but tight U.S. border security is forcing them to take bigger risks to get narcotics and illegal immigrants into the United States.
Tuesday's brazen attempt was unprecedented at the heavily guarded crossing where helicopters circle overhead and armed agents with dogs keep watch at a series of staggered checkpoints.
All the illegal immigrants were arrested and taken into custody and the crossing, a major smuggling corridor for narcotics and illegal immigrants, was shut while police carried out the investigation.
Some 90 million people a year use the California-Mexico land border crossings, with almost half the traffic going through San Ysidro alone.
Angry drivers started blaring car horns as a huge traffic jam built up on the Mexican side while U.S. agents signaled them to turn round.
"I've never known the entire crossing to be closed before. We just didn't believe the agents when they told us to turn around," said a Mexican student who gave his name as Juan Carlos and who crosses the border almost daily.
U.S. officials are directing motorists to California's other six border crossing, which also handle trucks.