US agents shoot tear gas at migrants attempting to breach Mexican border

The US closed its busiest border crossing with Mexico after Mexican police broke up a protest of migrants in Tijuana, scattering demonstrators towards the border where US agents hurled tear gas canisters.

Children were screaming and coughing in the mayhem on Sunday (local time).

Honduran migrant Ana Zuniga, 23, said she saw migrants open a small hole in concertina wire at a gap on the Mexican side of a levee, at which point US agents fired tear gas at them.

"We ran, but when you run the gas asphyxiates you more," she told the AP while cradling her three-year-old daughter Valery in her arms.

Mexico's Milenio TV also showed images of several migrants at the border trying to jump over the fence.

Metres away on the US side, shoppers streamed in and out of a shopping centre.

US Border Patrol helicopters flew overhead, while US agents held vigil on foot beyond the wire fence in California.

The Border Patrol office in San Diego said via Twitter that pedestrian crossings had been suspended at the San Ysidro port of entry at both the East and West facilities.

All north and southbound traffic was halted until the border was reopened several hours later.

Pedestrian crossings and vehicle traffic have since resumed, officials said.

During the protest earlier on Sunday, the several hundred Central American migrants, who pushed past the blockade of Mexican police standing guard near the international border crossing, appeared to easily pass through without using violence.

Some of the migrants called on each other to remain peaceful.

The migrants, who were demonstrating to pressure the US to hear their asylum claims, carried hand-painted American and Honduran flags while chanting: "We are not criminals! We are international workers!"

A second line of Mexican police carrying plastic riot shields stood guard outside a Mexican customs and immigration plaza.

That line of police had installed tall steel panels behind them outside the Chaparral crossing on the Mexican side of the border.

Migrants were asked by police to turn back towards Mexico.

As it became clear they would not be given permission to cross the border, a small group of migrants broke off, heading a few hundred metres away to a part of a canal between Tijuana and San Diego that led to the border fence.

The move prompted US Customs and Border protest officers to launch tear gas canisters at the waiting migrants.

After running to relative safety a few hundred metres away, hundreds of the caravan members held a sit-in.

Later, the migrants again approached the border in groups and were met by a further volley of canisters emitting large clouds of gas.

More than 5,000 migrants have been camped in and around a sports complex in Tijuana after making their way through Mexico in recent weeks via a caravan.

Many hope to apply for asylum in the US despite growing US measures to tighten the border.

Agents at the San Ysidro entry point are currently processing fewer than 100 asylum petitions a day.

Irineo Mujica, who has accompanied the migrants for weeks as part of the aid group Pueblo Sin Fronteras, said the aim of Sunday's march toward the US border was to make the migrants' plight more visible to the governments of Mexico and the US.

"We can't have all these people here," Mr Mujica said.

Tijuana Mayor Juan Manuel Gastelum declared a humanitarian crisis in his border city of 1.6 million on Friday.

Mr Gastelum said the city was struggling to accommodate the crush of migrants.

In the wake of the tear gas incident, the Mexican Interior Ministry announced in a statement it planned to deport about 500 of the migrants who tried to "violently" and "illegally" cross the border on Sunday.

The statement explained Mexican authorities had contained the protest at the crossing between Tijuana and San Diego and that, despite heightened tensions there, Mexico would not send military forces to control 7,417 migrants from the caravan at the US-Mexico border.

The Interior Ministry added the country had sent 11,000 Central Americans back to their countries of origin since October 19.

It said 1,906 of the migrants were members of the recent caravans.

Mexico is on track to send a total of around 100,000 Central Americans back home by the end of this year.

Taking to Twitter on Sunday, US President Donald Trump expressed his displeasure with the migrant caravan in Mexico.

Moments after the border was closed, Mr Trump issued a self-congratulatory tweet, quoting Brigadier General Anthony Tata.

The President has deployed military forces to the border to support the Border Patrol and threatened to close the entire southern border on Sunday.

Mr Trump also tweeted on Saturday that migrants at the US-Mexico border would stay in Mexico until their asylum claims were individually approved in US courts, but Mexico's incoming government denied any such deal had been struck.

AP/Reuters