Hurricane John on Monday slammed into Mexico’s southern Pacific coast as a major Category 3 storm, bringing warnings for residents to seek shelter indoors. John came ashore near Marquelia in Guerrero state, packing maximum sustained winds of around 120 miles (195 kilometers) per hour, the US-based National Hurricane Center said. “Damaging hurricane-force winds, life-threatening storm surge and flash flooding are ongoing,” it warned. “Slow-moving Hurricane John will bring very heavy rainfall to coastal portions of southwest Mexico through the upcoming week,” according to the NHC, which put John in the third-highest category on the five-step Saffir-Simpson scale. “This heavy rainfall will likely cause significant and possibly catastrophic, life-threatening flash flooding” in the southern states of Chiapas, Oaxaca and Guerrero, it said. A hurricane warning was in effect from east of Acapulco to Bahias de Huatulco on the Pacific coast.”After landfall, the system will rapidly weaken over the high terrain of southern Mexico,” the NHC said. President Andres Manuel Lopez Obrador earlier warned people living along the affected coastline to be prepared.