MEXICO CITY, March 23 (Xinhua) -- At least 1,200 Central American migrants left the Mexican city of Tapachula in Chiapas in a caravan Saturday and headed to the U.S. border, local authorities said.

The caravan, carrying migrants including pregnant women and children, left at around 4 a.m. (1000 GMT) from the city that borders Guatemala.

The Chiapas Secretary of Civil Protection told Xinhua that its personnel accompanied the caravan to attend to any possible emergency, while federal police would provide security along the road.

The migrants are mainly from Honduras, Guatemala and El Salvador, according to local media reports.

Mayor of Huixtla offered transportation to the Central Americans to make their journey quicker in hot weather. However, the migrants refused the offer, Cipriano Hernandez, director of the Civil Protection told Xinhua.

He estimated there were between 1,200 and 1,500 people in the caravan.

"We're worried about the pregnant women and children, but we respect their decision," Hernandez told Xinhua by phone, adding that the mayor's office will offer help if they choose to stop in Huixtla to spend the night.

Since October, thousands of Central Americans have entered Mexico in caravans to pass through the country to seek asylum in the United States, which has beefed up security along its border in recent months facing a stream of incoming migrants.

The Mexican government has said it has been working with Washington since December to develop an integral plan in Central American countries, with the goal of reducing poverty and violence among the local population.