Gunmen have launched a string of attacks on federal police bases in Mexico, killing five people.
At least six cities were hit - all in the western Michoacan state, a stronghold of Mexico's drug cartels.
Three police officers and two soldiers are reported to have been killed when the attackers, armed with grenades and assault rifles, opened fire.
In one incident, in the state capital Morelia, 40 gunmen arrived in a convoy of vehicles to carry out the raid.
There had already been prolonged gun battles in the city on Friday, during which suspected drug boss Arnoldo Rueda - a senior member of the La Familia Michoacana drug cartel - was arrested.
The co-ordinated raids are being seen as a revenge attack for that arrest.
As well as Morelia, the cities of Apatzingan, Lazaro Cardenas, Patzcuaro, Zitacuaro and Huetamo were targeted.
Mexican President Felipe Calderon - who comes from Michoacan - has launched a major operation to try to stem the country's drug violence, deploying tens of thousands of extra troops and police officers.
Some 6,000 people died in violence related to organised crime last year.