Bay Area members of Congress responded on Monday to the U.S. Customs and Border Protection's use of tear gas on migrants at the U.S.-Mexico border over the weekend.

Agents reportedly used tear gas at the San Ysidro Land Port of Entry, which was shut down for some time Sunday. Tensions flared after scores of migrants broke off from a protest march in Tijuana and tried to get over the border and into the United States. The migrants who continued to the border were met by U.S. border agents who sprayed tear gas.

Peninsula congresswoman Jackie Speier called for an investigation into whether Sunday’s use of tear gas constitutes undue force.

"Seeing moms with children in diapers being repelled by it doesn’t seem appropriate," she said.

Meanwhile, East Bay Rep. Eric Swalwell said the incident raises serious questions.

"Tear gas is a form of chemical weapon and I’m interested in learning more about whether any treaties were violated," he said.

Swalwell added that Democrats will take a look at the situation at the border after they take control of the U.S. House of Representatives in January.

"In a new Congress, we will make sure that we do all we can to use our leverage to make sure that families at the border are not separated, that we are not funding the use of tear gas or any other type of weapon and that we are conducting oversight to make sure that we are not violating any international laws by using our military either to engage with another country at the border or to have our military perform law enforcement duties without being properly being designated to do so," he said.

In a tweet, East Bay congresswoman Barbara Lee repeated her call for United Nations inspectors on the border.

In recent months, thousands of migrants from Central America have arrived in Tijuana, many hoping to seek asylum in the U.S. But that process is extremely slow.

KQED reported on Nov. 21 that there were already more than 4,000 names on a list of people waiting to be processed for asylum.

Mexican officials are calling for the U.S. to improve the process. But the Trump administration has focused on "hardening" the border and preventing illegal entries.