CIUDAD JUAREZ, Mexico — Some 2,000 police are hunkering down in hotels in Mexico's most violent city of Ciudad Juarez after a drug gang threatened to kill an officer per day if their chief refused to resign.

Eleven police officers, including four commanders, have already been killed in the city across from El Paso, Texas, since the start of the year.

The city's mayor this week ordered police to use several local hotels as temporary barracks to protect themselves from attacks on the way home from work in the city at the heart of Mexican drug violence that has left 50,000 dead in five years.

Mayor Hector Murguia said Tuesday that they would stay in hotels for at least three months, with 1.5 million dollars put aside to pay for it.

Murguia stood by his police chief, Julian Leyzaola, a controversial former soldier who has also been asked to resign by human rights groups for his alleged heavy-handed policing.

"The chances that he (Leyzaola) resigns or that they force him to resign are zero percent," the mayor told journalists.

At the entrance to the Rio motel, on Las Torres avenue, several patrols stand guard to protect access to the improvised barracks, as others monitor vehicles passing by.

Last week, several banners signed by the "New Cartel of Juarez" appeared around the city of 1.3 million, to announce the killing of a police officer each day as long as Leyzaola stayed in charge of the local police.

Some of the messages also accused the police chief of protecting another group, "New Generation," allied to powerful Sinaloa drug cartel of fugitive billionaire Joaquin "El Chapo" Guzman.

According to the mayor, the threats only showed how concerned the drug gangs were in the face of Leyzaola.

Murders fell to less than 2,000 in the city in 2011 -- the year Leyzaola took control -- from 3,100 in 2010. Key leaders of city gangs like the "Aztecas" were also captured.

Leyzaola already provoked controversy when he led police in another Mexican border city, Tijuana in northwest Mexico.

Authorities lauded him for reducing crime there but organizations such as Amnesty International sought to put him on trial for the alleged torture of prisoners, backed by witness accounts from at least 25 police.

Since Leyzaola took over the local police in Ciudad Juarez in March 2011, the Chihuahua state human rights commission has recorded 37 complaints against him, including for abuse of authority and arbitrary detentions.

Gustavo de la Rosa, a commission member, told AFP that the police "were told to arrest anyone who looked like a criminal or became nervous on seeing someone in uniform."

The business community of Ciudad Juarez -- the base of almost 20 percent of Mexico's manufacturing industry -- support the police chief, however.

"It's clear that we have to stop the violence continuing, particularly murders of police. We have to look for means to reinforce the local police," said Alejandro Seade, director of the city's chamber of commerce.