A federal police checkpoint set up on the southbound lanes of the Manzanillo-Colima highway this weekend caused a four-kilometer tailback near the town of Tecoman.
Motorists traveling from the port city complained of delays of more than one hour.
News reports said officers were on the lookout for stolen merchandise and weapons.
Almost two-thirds of the 107 homicides committed in the state of Colima this year have occurred in Tecoman.
There are no indications of when the road block might be lifted.