Thirteen people, including a police officer, were killed in Mexico's northern Chihuahua state, officials have said, as regional prosecutors held a security crisis meeting in the state capital.
The deaths followed the signing, by politicians and prosecutors, of a nationwide security pact in Mexico City on Thursday in a bid to tackle a spike in drug-related murders and kidnappings in recent months.
Violence has escalated throughout Mexico since President Felipe Calderon, who took office at the end of 2006, launched a military crackdown on drug trafficking.
Most of Friday's deaths were in Ciudad Juarez -- across the Rio Grande from El Paso, Texas -- which has the highest murder toll of the country this year, with more than 800 killed.
A group of masked men armed with AK-47s killed a local police commander outside Ciudad Juarez, a town hall official told AFP. Later, a group armed with assault rifles killed four men travelling in a vehicle in the town center, local police said.
Other deaths included three businessmen killed in firearm attacks, and a man shot more than 100 times with AK-47s, officials said.
Prosecutors from across the country met in Chihuahua, the state capital, in the first steps of the new security pact.
The 74-point accord includes a police purge, strategies against money-laundering and drug-trafficking, and the creation of two federal prisons for kidnappers.