Hector Murguia, a member of the Institutional Revolutionary Party, or PRI, said he would work to restore peace to Ciudad Juarez, located across the border from El Paso, Texas.
Murguia, who won the mayoral election on July 4, became the first person in Juarez’s history to be elected mayor twice.
The new mayor faces a tough task in trying to reduce crime in the border city.
Ciudad Juarez is the scene of a war for control of smuggling routes into the United States between the Juarez and Sinaloa drug cartels.
More than 90 police officers from different agencies and departments have been murdered this year in drug-related violence in Ciudad Juarez.
A total of 32 municipal police officers have died in shootouts, ambushes and gangland hits since January, according to figures provided by prosecutors, while 23 Federal Police officers have been killed.
Over the weekend, two simultaneous fights between members of the Los Aztecas and Los Mexicles gangs at two different prisons in Ciudad Juarez left at least two inmates dead and 17 others wounded.
Three guards were also hurt in the incidents Saturday at the municipal jail in Ciudad Juarez and at the state prison in the northern border city, officials said.
Army troops and Federal Police officers restored order in the prisons.
The Los Aztecas gang, which is linked to the Juarez drug cartel, controls the prisons and 80 percent of the drug dealing in the border city, U.S. intelligence reports say.
Los Mexicles, the main rival of Los Aztecas, is believed to be linked to the Sinaloa cartel, Mexico’s oldest and largest drug trafficking organization.
The border city, where more than 2,200 people have been murdered this year, has been plagued by drug-related violence for years.
The murder rate took off in the border city of 1.5 million people in 2007, when more than 800 people were killed, then it more than doubled to 1,623 in 2008, according to press tallies, with the number of killings soaring to 2,635 last year.
Ciudad Juarez, with 191 homicides per 100,000 residents, was the most violent city in the world in 2009, registering a higher murder rate than San Pedro Sula, San Salvador, Caracas and Guatemala, two Mexican non-governmental organizations said in a report released earlier this year.
The death toll from the drug war in Ciudad Juarez totaled 8,300 between December 2006 and July 2010.
The violence has prompted thousands of Juarez residents to leave for other parts of Mexico or neighboring El Paso.
Some 230,000 people have left Ciudad Juarez in the past three years as the death toll from the gang war topped 7,000, a non-governmental organization said in a recent report.
About 124,000 people, or 53.9 percent of the total, have sought safe haven in El Paso, the Ciudad Juarez Citizens Security and Coexistence Observatory said.
The rest have returned to their hometowns, mainly in Durango, Coahuila and Veracruz states, to get away from the drug-related violence.
More than 20,000 houses have been abandoned in the border city by people who feared they might become murder, extortion or kidnapping victims, former Ciudad Juarez Mayor Jose Reyes Ferriz said recently.