border patrol
The western most tip of U.S.-Mexico border fence stretches into the Pacific Ocean in this Oct. 3, 2013 photo taken in San Diego, California. A female undocumented immigrant died Thursday after a boat she was traveling in collided with a U.S. Border Patrol vessel. John Moore/Getty Images

One woman died Thursday after a boat that was packed with undocumented immigrants collided Thursday with a U.S. Border Patrol vessel in Southern California, according to a new report. At least four other undocumented immigrants were hospitalized after the collision, which happened off the coast of the North County in Oceanside, California, near San Diego, ABC affiliate 10 News reported.

The undocumented immigrants were allegedly being smuggled into the U.S. Thursday morning when agents from the U.S. Customs and Border protection spotted the boat they were in and attempted to stop it. However, the boat ignored the orders despite warning shots from agents before the collision, resulting in all 20 of the people on the smuggling boat ending up in the water and the boat capsizing.

It was unclear which boat initiated contact, and at least one advocate for undocumented immigrants questioned the account that was provided by U.S. Border Patrol. "It's very unfortunate that there was a loss of life, but we also question the need to fire warning shots specifically when that might deter or scare people from actually making contact with CBP," Pedro Rios, of the American Friends Service Committee, said to NBC San Diego. "In this case, it's unclear who struck who, but we do know there was a fatality and that's very unfortunate."

It was unclear if the boat was only transporting humans or if illegal drugs were involved as well.

Undocumented immigrants and their attempts to enter the U.S. illegally has been keeping Border Patrol agents especially busy as of late, but recently a spokesperson for the group has complained that agents' power to enforce rules and regulations surrounding illegal immigration have been stymied. One agent in San Diego told the Los Angeles Times that the U.S Customs and Border Patrol agency no longer wants them conducting drug busts, a key part of the job. “There was a lot of pressure for us to get out of the [drug] interdiction game,” said Shane Gallagher.