Eleven people, eight of them women, were killed in simultaneous shooting attacks on two bars in north-central Mexico, authorities said on May 24.
Handwritten signs left at the scenes of the killings suggested the attacks were part of a rivalry between two drug cartels that have been battling for control of Guanajuato state for several years.
Police in the city of Celaya said the attacks occurred late on May 23 at two bars on the same street. They said 10 of the victims died at the scene, and another was declared dead at a hospital later.
Police confirmed that messages were left at the scene, but did not confirm what they said. But photos posted on social media suggested the killers were from the Santa Rosa de Lima gang. The messages appeared to accuse the bars' owners of supporting the rival Jalisco cartel.
The photos showed women — it was not clear if they were bar employees or customers — heaped in pools of blood between tables. Part of one bar also appeared to have been partly burned.
