Nicaraguan police have detained 18 people, including a Mexican policeman, posing as journalists while trying to enter Honduras with millions of dollars in cash, the country's police chief said on Friday.

The group was detained on Monday as it tried to cross into Nicaragua with the cash in six vehicles, Nicaragua's national police commissioner Aminta Granera told a news conference.

"There's certainly no less than $7 million in the stashes we found hidden in the six Chevrolet pickup trucks," Granera said, flanked by police chiefs from Colombia, Mexico and the Caribbean, who had gathered in Managua for a regional crime-fighting conference.

She said the group had posed as reporters from Televisa, Mexico's largest broadcaster, adding police found video cameras, audio equipment, microphones and satellite phones in the vehicles as well.

Several of the detainees, including the police officer, have been confirmed as Mexican citizens, she said.

Nicaraguan authorities, who also confirmed the detainees had no link to Televisa, are now working with Interpol to see whether they belong to any criminal organizations, she added.

Interpol had indicated one of those detained was a police officer from the Mexican state of Durango, she said.

Organized drug-running cartels have cultivated Central American supply lines as Mexico's government wages a military offensive against the gangs throughout the country.

There have been more than 55,000 drug related killings in Mexico since President Felipe Calderon took office in late 2006.