Four people were killed and 16 wounded after unidentified gunmen carried out separate attacks on two bars in Mexico's second biggest city, officials said Monday.
Two men were killed and nine people were wounded in the western city of Guadalajara late Sunday when a shooter burst into a bar where people had just watched the Chivas-America football derby, authorities said.
"Without saying a word, he began to open fire," the Jalisco state prosecutor's said in a statement, adding that the killer had arrived with other accomplices in two vehicles.
One of the victims was a US citizen, local media said. The US consulate and the prosecutor's office did not confirm the victim's nationality.
Minutes after the first attack, gunmen entered another bar nearby, killing a 28-year-old waiter and another 25-year-old man, and wounding seven people. The assailants had thrown an explosive but it was unclear whether it caused injuries.
One of the wounded was a 15-year-old girl, city police told AFP.
Authorities were unable to confirm whether the same gunman was responsible for both attacks.
Four other men were killed in other attacks on Sunday across Guadalajara, which has endured some of the drug-related violence that has left 70,000 people dead in Mexico since December 2006.