MEXICO CITY (AFP) - Six Mexican states were on high alert for a strengthening Hurricane Marie, warning that torrential rain could trigger mudslides and cause rivers to break their banks.

Marie, the eighth hurricane of the eastern Pacific season, was packing maximum sustained winds of 165 km per hour - increasing it to a Category Two storm on the Saffir-Simpson scale, according to the Miami-based National Hurricane Centre (NHC).

It said the storm was continuing to gain strength, and cautioned it would likely become a major hurricane by Monday.

Marie was far from land and no storm watches or warnings were in effect for the coast. However, the NHC said portions of Mexico's south-western coast were already seeing powerful waves as a result of Marie, and the impact was likely to spread toward the southern Baja California peninsula and the Gulf of California as the storm strengthens and moves to the northwest.

"These swells are likely to cause extremely dangerous life-threatening surf and rip current conditions," the forecasters warned.

In Mexico, the national weather service said heavy rains threatened the states of Michoacan, Colima, Guerrero, Oaxaca, Jalisco and Nayarit. It urged the millions of people living in those states to "exercise caution" and to stay tuned for updates.