Mexico City (AFP) - A Mexican judge has charged three people with terrorism over their roles in a day of violence launched by a drug cartel in Jalisco state last week, authorities said.

The suspects were accused of organized crime "with the goal of committing ... terrorism" by burning vehicles and using them to block roads around Mexico's second biggest city, Guadalajara, the Federal Judicial Council said.

Three other people were released because they were "arbitrarily" detained, the council said.

Authorities say the Jalisco New Generation drug cartel launched gun fights and burned several vehicles, banks and gasoline stations across the state on May 1 to hit back at a federal operation to dismantle the gang.

The gang is accused of using a rocket-propelled grenade to down an army helicopter that was pursuing vehicles suspected of carrying a cartel leader.

The interior ministry raised the death toll from the downing to eight after a federal policewoman and a soldier succumbed to their wounds. Six other troops had died.

The attack on the Cougar helicopter, which was carrying 18 troops and police, was a first by a Mexican cartel against such a military aircraft.

In addition to the eight helicopter deaths, officials say eight gang suspects and a state police officer were killed in other confrontations on May 1.

The New Generation has attacked authorities several times this year, killing 20 police officers in two ambushes in March and April, and turning Jalisco into a new challenge for embattled President Enrique Pena Nieto.

Pena Nieto's administration has vowed to crush the cartel led by Nemesio "El Mencho" Oseguera.

On Thursday, soldiers set up checkpoints on several important roads in the southern part of the state, where much of the violence has taken place.



