Several people were killed in a gunbattle between soldiers and suspected drug smugglers in northern Mexico on Friday, a government source said, with national media reporting a massive seizure of cocaine.
The shootout happened during an anti-drugs operation in the port city of Tampico, home to the Gulf Cartel, one of the two most powerful Mexican drug gangs.
"We're talking about several deaths," said the official, who asked not to be named and did not provide further details, including whether any cocaine was seized.
Mexican newspapers reported on their Web sites that up to 15 people died in the fighting, which began when traffickers shot at soldiers conducting anti-drug operations.
Radio and online reports said the army seized up to 20 tonnes of cocaine after the battle.
More than 2,000 people have been killed this year in violence involving rival drug gangs and the government.