A migration crisis at the border between Chile and Peru intensified Thursday as hundreds of people remained stranded, unable to cross into Peru in an effort to return to their home country of Venezuela.

The mostly Venezuelan migrants are seeking to cross into Peru to continue on to their home country but Peru isn’t allowing them to enter because they lack documents.

While stalled at the border of the two South American countries, the migrants face the inhospitable climate that characterizes the Atacama Desert, one of the driest on the planet, with extremely hot days and intensely cold nights. Some have improvised tents with blankets but they lack water and other basic services.

A group of migrants ran through the desert toward Peru, but they were turned back by Peruvian officers. Some women complained and demanded that the government of President Gabriel Boric provide a bus for them to travel to Venezuela.

Images showed migrants shoving Peruvian border patrol officers in an effort to enter the country.

Officials in Arica, the northern Chilean city that borders Peru and is around 2,000 kilometers (1,245 miles) from the capital of Santiago, declared a migration emergency Thursday.