20 killed in clashes between cartels, federal police in Michoacan

Mexico's rough western state of Michoacan is proving to be just as painful a thorn in the side of President Enrique Pena Nieto as it was for predecessor Felipe Calderon.

Coming off a stunning success with the capture of Zetas cartel leader Miguel Angel Trevino Morales, Pena Nieto almost immediately was plunged back into the bloody reality of Mexico's drug war this week.

Gunmen believed to be working for the Knights Templar cartel staged coordinated ambushes on federal police convoys Tuesday.

Attacks continued on Wednesday, wounding at least five federal police officers. The death toll from Tuesday's clashes stood at 20 gunmen and two federal police.

The cartel's deep local roots and proven capacity for violence could make Michoacan the graveyard of Pena Nieto's pledge to reduce drug violence.