LOS ANGELES (NewsNation Now) — A migrant caravan attempting to walk across southern Mexico is now headed to the U.S. border rather than Mexico City as originally planned.

Earlier this week, leader and immigration activist Irineo Mujica said he’ll try to organize another caravan of thousands of migrants to reach the Gulf coast state of Veracruz, where both groups will join up and set out for the border.

The apparent change in plans comes after Mujica said the group has been pursued and harassed by Mexican government officials. Relations deteriorated after a group of migrants pelted officers of Mexico’s National Guard with a hail of rocks Thursday, injuring five guard officers.

The change of plans may be an act of desperation: the group is dwindling after more than two weeks of walking through punishing heat, and now may number as little as 1,300 people. It had once been as large as 4,000.

But since they set out from the city of Tapachula on Oct. 23, the group has managed to make it only about 190 miles.

Sources tell NewsNation that this caravan would likely end up near the Arizona border.

The Mexican government has been attempting to discourage the march, saying the poor conditions and extreme heat are putting the migrants’ lives at risk. The National Immigration Institute said six cases of the tropical fever dengue had been detected among members of the migrant march.

The migrants set out from the city of Tapachula, near the Guatemalan border, on foot. They claimed that Mexican immigration authorities were taking too long to process visa requests and were using Tapachula as a holding point to prevent migrants from going north.

Much larger caravans crossed Mexico in 2018 and 2019, but those migrants never tried to walk the whole distance. They usually caught rides aboard passing trucks.

But Mexico has told truckers not to pick up migrants, saying they could face charges of migrant trafficking.