Hurricane Adrian, the first of the season in the Pacific, continued to strengthen in the early hours of Friday - but remained far from Mexico's coast, dpa reported. The Miami-based US National Hurricane Centre (NHC) noted that Adrian appeared to be "peaking in intensity." It had become a category-four hurricane on the five-tier Saffir-Simpson scale, with sustained winds of up to 220 kilometres per hour and higher gusts. Its centre was about 500 kilometres southwest of Manzanillo, in the Mexican state of Colima, and it was moving northwest at 15 kilometres per hour. Adrian was expected to start weakening later Friday or Saturday, the NHC said. Although the hurricane was not expected to make landfall in Mexico, Mexican Civil Protection officials urged for caution in the states of Colima, Michoacan, Guerrero and Oaxaca because of the rain, wind and waves associated with the storm.