U.S. agents gun down immigrant fleeing Mexico border crossing

According to authorities, U.S. customs officers at the the San Ysidro entry port for processing pedestrians were involved in the shooting after a 47-year-old man pulled out a starter pistol and fired it.

The unidentified man is currently undergoing medical treatment for injuries sustained in the altercation.

Mexican police and paramedics quickly converged on the scene as they eagerly awaiting for information from the other side of the border about the incident.

"All we have asked for is support. For now we have closed the crossing for pedestrians as we heard of an incident involving a firearm. The police that we now have here are just here for support because we don't know exactly where he was going or the place he was headed. They say that there were shots fired," said Director of the Tijuana Municipal Police, Adrian Hernandez.

Coaches loaded with immigrants suspended their normal operations as police took over the border crossing and stranded thousands of confused passengers.

"No we don't know if there was a kidnapping or something," said a man at the border.

With little information on the ground, concern quickly spread amongst those waiting to pass the border fearing the worst with the popular crossing point also used by crime gangs ferrying drugs and illegal migrants north.

"No they haven't told us anything. (INTERVIEWER: Were you scared?) More of less, for the people that were running but they haven't told us anything," said a woman at the crossing point.

Some 90 million people use this California-Mexico land border crossings each year with almost half the traffic going through San Ysidro alone.