Washington D.C. (CNA) Catholic groups have reacted to the use of tear gas at the U.S. - Mexico border Sunday, calling the situation “sad,” and expressing concern about the instability of the situation at the border.

The comments came in response to an incident Nov. 25, in which U.S. Customs and Border Patrol deployed tear gas against a crowd at the San Ysidro border crossing near Tijuana, Mexico.

The incident, which closed the port of entry, involved migrants from the so-called “migrant caravan” from Central America, many of whom have expressed a desire for asylum status in the United States. Some members of the caravan, which has been in Tijuana for the past several days, attempted to enter the U.S. in a large group, resulting in a confrontation with Mexican law enforcement.

U.S. border officials said that officers had rocks and other objects thrown at them from the crowd. In response, the border was closed for several hours and tear gas was used to break up the group.

The use of tear gas is not permitted by international law in situations of war, but is permitted for law-enforcement use.

“We are sad that such force has been used,” said Bill Canny, the executive director of the USCCB’s Migration and Refugee Services, in a statement provided to EWTN.

“The reports of better cooperation between Mexico and the US are encouraging as this is an important border issue for both countries. We are of course most interested in the well-being of those fleeing violence, persecution, and severe economic deprivation, and expect our laws and international laws vis a vis asylum seekers and migrants will be respected,” he added.

Canny’s sentiment was echoed by Lawrence E. Couch, the director of the National Advocacy Center of the Sisters of the Good Shepherd.

In a statement, Couch said the use of tear gas on the caravan represented a “sharp escalation” of the immigration crisis.

“When we start to tear gas women and children, we know we have gone down the wrong road,” said Couch, calling it “our duty and moral imperative to protect and welcome our brothers and sisters.”

Kevin McAleenan, commissioner of U.S. Customs and Border Protection, defended on Sunday the agency’s response. In a statement released on Twitter, McAleen said that the situation was “extremely dangerous” and involved over 1,000 members of the caravan.

“(Sunday)’s incident involved large groups of migrants ignoring and overwhelming Mexican law enforcement, then attempting to enter the United States through vehicle lanes at San Ysidro and El Chaparral, and then through breaches in the international border fence between ports of entry,” said McAleenan.

Some members of the group assaulted agents and officers, he said. Four agents were hit with rocks thrown by members of the crowd, but none were seriously injured due to protective gear.

While the use of tear gas Sunday attracted strong media coverage and reaction, U.S. Customs and Border Patrol has deployed the measure multiple times in recent years. Between the years 2012 and 2016, tear gas was used 79 times along the border.