The Central American migrants are heading north towards the United States. The migrants are mainly from Honduras and are being monitored by a municipal police patrol.
A caravan of around 1,200 Central American migrants entered southern Mexico on Wednesday bound for the United States, police said, even as President Donald Trump threatened Mexico with tariffs if it fails to slow illegal immigration.
Authorities did not deter the large group of undocumented migrants who crossed the bridge over the Suchiate river, which forms the border between Guatemala and Ciudad Hidalgo, Mexico.
A municipal police patrol monitored the migrants – who were mostly from Honduras – but did not stop them as they began walking along the side of the road in the southern state of Chiapas toward the city of Tapachula.
Mexico has deployed its new National Guard police force to the southern border and stepped up detentions and deportations in a bid to slow the flow of migrants crossing its territory toward the United States.
But migrant detentions at the US-Mexican border still increased by 32 percent month-on-month in May, to more than 144,000, according to US Customs and Border Protection.
That has provoked the wrath of the US president, who threatened last week to apply tariffs of five percent on all Mexican exports starting on Monday and rising incrementally to 25 percent by October.
A high-level delegation led by Mexican Foreign Minister Marcelo Ebrard was due to meet with US Vice President Mike Pence and Secretary of State Mike Pompeo later on Wednesday to seek a deal to avoid the tariffs.
The number of migrants crossing Mexico toward the United States has surged in recent months. They are mainly Central Americans fleeing poverty and violence, often travelling in families – and sometimes in large caravans travelling together for safety.
Central American countries are working on a regional plan to slow the exodus of people fleeing poverty and brutal gang violence that have made El Salvador, Guatemala and Honduras among the most dangerous countries in the world.
At a meeting of regional bloc SICA in Guatemala City, Guatemalan President Jimmy Morales said the countries of Central America had "worked very intensely to develop a plan of action to fully attend to migration in the region."
He did not give details on the forthcoming plan, or say when it would be published.