MEXICO CITY - Scores of Central American migrants seeking to cross the US-Mexico border ran from tear gas fired by US border agents near US border fence, Mexican Interior Minister Alfonso Navarrete said on Sunday.

Navarrete said a group of asylum-seekers on Sunday tried to break through to the other side, leading Mexican authorities to reinforce police presence at several border points in the northwestern city of Tijuana, located some 3 km from the United States.

"It will be a police operation. We are in no way going to deploy military troops, because that is not President Enrique Pena's order or conviction," he said during an interview with television news channel Milenio.

The instigators of the incident will be deported back to their countries once identified, the minister said.

Earlier, US Department of Homeland Security Secretary Kirstjen Nielsen said in a statement that the port of entry was closed "to ensure public safety in response to large numbers of migrants seeking to enter the US illegally."

"That is not the way to do it, and they somehow knew they were not going to be able to get into US territory like this," Navarrete said.

On Friday, the mayor of Tijuana, Juan Manuel Gastelum, declared a humanitarian crisis, saying the city lacks the infrastructure to handle the influx of 5,000 migrants.

Mostly from Honduras, but also El Salvador and Guatemala, the migrants have trekked thousands of kilometers to reach Tijuana.