PARIS (AP) — A U.N. migration official says Algeria's government has resumed expelling migrants into the Sahara Desert to die.

The head of the U.N.'s International Organization for Migration in Niger, Giuseppe Loprete, tweeted Saturday that 391 migrants from 16 countries were abandoned at the border. The Associated Press reported last month that Algeria has left more than 13,000 migrants in the desert of Niger and Mali since May 2017, forcing them to walk or die under searing heat.

For several weeks, the expulsions appeared to have been suspended. An aid worker with contacts inside Algeria said the government instead was keeping migrants incommunicado for weeks in detention centers.

IOM has found many migrants as they stumble through the desert. Many told the AP they saw deaths along the way.