JUAREZ, Mexico (CNN) -- The mayor of Juarez announced Friday that the city's police chief is stepping down after receiving death threats from local drug cartels.
Police Chief Robert Orduna's resignation also came in response to the deaths of other police, Mayor Jose Reyes Ferriz told reporters.
"The police chief has resigned, saying he did not want to be responsible for any more police dying," Reyes said.
But observers should not interpret the resignation as a capitulation to narcotraffickers, he said. Watch CNN's Michael Ware discuss police chief's departure »
"We have not blinked," Reyes said. "We will continue to fight organized crime... he has done a good job, but we will find someone else."
The change in command in Juarez's police force comes in the wake of a campaign of intimidation by a drug cartel that has the border city in its grip.
Federal police and local police have locked down much of Juarez, which lies across the border from El Paso, Texas. It serves as a major transit point for the smuggling of cocaine, marijuana and methamphetamine into the United States.
Orduna, who replaced half of the 1,600-person police force with new recruits in a bid to rid it of corrupt members, tendered his resignation to protect the men who serve him, Reyes told reporters.
"They started killing police officers when they were going home or getting into police cars," he said.
The police director of operations was gunned down on Tuesday in his car. Another police officer and a prison guard were found dead Friday morning as part of a campaign of intimidation against government forces blamed on the cartels.
Last year, more than 100 police were killed in Juarez in attacks blamed on organized crime.
On Friday, the U.S. State Department renewed a travel alert for Americans considering a visit to Mexico.
"The situation in Ciudad Juarez is of special concern," it said. "Mexican authorities report that more than 1,800 people have been killed in the city since January 2008. Additionally, this city of 1.6 million people experienced more than 17,000 car thefts and 1,650 carjackings in 2008."
Drug-related violence in Mexico has continued unabated since December 2006, when President Felipe Calderon took power and launched an offensive against the cartels.
Last year, drug violence was blamed for the deaths of 78 Mexican soldiers and more than 6,000 civilians.
CNN's Ismael Estrada, Michael Ware and Rey Rodriguez contributed to this report from Juarez, Mexico.