SAN SALVADOR, El Salvador — El Salvador’s government is demanding that telephone companies completely block cellphone signals inside the country’s prisons, in a bid to stop gang leaders from ordering killings and other crimes from behind bars.

President Nayib Bukele, who took office June 1, is moving to crack down on gangs in the crime-plagued Central American country where many are forced to flee toward the United States to escape violence and gang threats.

Bukele’s predecessor, Salvador Sánchez Cerén, declared a state of emergency in El Salvador’s prisons in 2016, transferring high-ranking gang members and asking phone companies to block cellphone signals to prevent jailed Mara Salvatrucha and Calle 18 leaders from running their operations while incarcerated.

The new president’s justice and public security minister, Rogelio Rivas, said at a news conference Friday that the phone companies had given him a report saying that “there is a signal in the prisons and the inmates can make calls.”

“We have bluntly asked the telephone companies that there be no signal within 72 hours, neither data nor calls, from penitentiaries,” Rivas said.

When announcing his security plan recently, Bukele complained that phone companies were not blocking the signals.

El Salvador is one of the most violent countries in the world. Its homicide rate last year was 50.3 killings per 100,000 inhabitants, or 9.2 a day.