Canadian and American visitors to Mexico are being told to be on alert in the country's popular Puerto Vallarta and Guadalajara areas, where violence between drug cartels and police has intensified in recent days.

The Embassy of Canada in Mexico has issued a warning advising Canadian travellers to "limit their movements" in the state of Jalisco, on Mexico's west coast. "Narco-blockades have been affecting areas in and around Puerto Vallarta and Guadalajara," the embassy said in a Facebook post.

Canadians in Jalisco are being told to remain vigilant and stay in touch with their emergency contacts in Canada. "Local authorities have advised to remain at home," the embassy said. "Avoid demonstrations and large gatherings."

The U.S. embassy in Mexico has issued a similar warning to its citizens.

At least nine people were killed in cartel-related violence in Jalisco on Friday, Mexican security officials said. Banks and gas stations were burned, and cartel members forced a military helicopter down using a rocket-propelled grenade.

The fighting erupted on the first day of a renewed push by Mexican authorities to stamp out organized crime in Jalisco and other problematic areas of the country.

Gang violence has been a growing problem in Jalisco. Last month, 15 state police officers were killed in an ambush by suspected members of the Jalisco New Generation cartel.

Puerto Vallarta is a popular destination for Canadian travellers and retirees.

With files from the Associated Press