A police chief and two of his bodyguards were killed and another police officer was wounded in an attack by suspected cartel gunmen in the Mexican Gulf coast state of Veracruz.
The deaths bring to nine the number of police officers killed by alleged members of criminal gangs in less than a month in different parts of Veracruz.
According to investigators' reports, the police personnel came under attack by six gunmen in the El Naranjito neighbourhood of the town of Cosoleacaque.
The slain men were the deputy coordinator of the Minatitlan-Cosoleacaque Inter-Municipal Police force, Juan Moreno Lopez, and his bodyguards, Alvaro Olguin Chagala and Moises Ramos.
One police officer also was wounded and another has been reported missing.
Army soldiers and local police officers launched an operation to locate the assailants.
On April 4, a police chief and five officers under his command were killed in an armed clash with suspected cartel gunmen in a rural area outside the Veracruz town of El Higo, near the border with the violence-wracked northeastern state of Tamaulipas.
Veracruz has seen constant fighting over the past four months between different federal forces and suspected enforcers for drug traffickers.