SAN YSIDRO, Calif. -- U.S. Customs and Border Protection officials shut down several lanes of traffic Tuesday at the San Ysidro and Otay Mesa ports of entry to install equipment in preparation for the arrival of the migrant caravan.
The agency shut down three northbound lanes at the San Ysidro Port of Entry and one lane at the Otay Mesa Port of Entry, the two busiest border crossings in the country, at 8 a.m.
The lanes will be closed indefinitely to install equipment "in preparation for the migrant caravan and the potential safety and security risk that it could cause," according to the agency.
A subgroup of the caravan totaling roughly 350 people arrived in Tijuana Tuesday aboard a caravan of trucks, well ahead of the larger caravan. Another group of 80 arrived in Tijuana Sunday, the first members of the caravan to arrive at a border crossing. All members of the caravan plan to seek asylum once they reach the border.
On Thursday, 1,100 Marines from Marine Corps Base Camp Pendleton were deployed to the U.S.-Mexico border to support border security, mainly by installing concertina wire and pre-positioning jersey barriers, barricades and fencing under Operation Secure Line.
"CBP has been and will continue to prepare for the potential arrival of thousands of people migrating in a caravan heading towards the border of the United States," Pete Flores, director of San Diego field operations for Customs and Border Protection said in a statement.
Customs and Border Protection officials recommend that motorists crossing from Tijuana into San Diego should expect increased wait times because of the lane closures. Local news footage Tuesday afternoon showed long lines and severe traffic due to the closures.
The closures are expected to last "until sometime after people in the caravan arrive to the border," the agency said.
On Thursday, a group of 5,000 migrants, mostly from Honduras, voted to proceed from Mexico City to Tijuana. It was unclear when the bulk of the caravan would reach the U.S. border.
President Donald Trump has vowed to prevent the caravan from entering the country, even threatening to shut down border crossings entirely.