MEXICO CITY, Mexico (AFP) — At least two people died after Hurricane John slammed into Mexico’s southern Pacific coast overnight, authorities reported Tuesday, with the cyclone since downgraded to a tropical storm and expected to weaken further.

Forecasters nevertheless warned of strong rains and flash floods inundating the coast for the next few days.

“Two people were reported dead due to a landslide in their home” in the southern city of Tlacoachistlahuaca, Evelyn Salgado, the governor of the Mexican state of Guerrero, told a press conference.

The US-based National Hurricane Center (NHC) warned of intense rainfall in coastal areas of southwest Mexico this week.

“This heavy rainfall will likely cause significant and possibly catastrophic, life-threatening flash flooding and mudslides” in the southern states of Chiapas, Oaxaca and Guerrero.

Authorities had warned residents to seek shelter as strong winds and rain battered beaches ahead of John making landfall near Marquelia in Guerrero.

The NHC said maximum sustained winds weakened to around 50 miles (85 kilometres) per hour — after earlier topping 120 mph —  according to a 1200 GMT update.

“Additional rapid weakening is anticipated, and John is expected to become a tropical depression later today,” the NHC said.

Through Thursday, John was forecast to produce up to 15 inches of rain in parts of Chiapas, and nearly double that in areas of Oaxaca and Guerrero, it said.

“John is producing extraordinary rains (greater than 250 mm) (9.8 inches) in Oaxaca and Guerrero; torrential rains in Chiapas,” the National Civil Protection agency said in a post on X early Tuesday.

The agency had issued a red alert on Monday, telling people to stay indoors and keep away from windows.

President Andres Manuel Lopez Obrador told his morning press conference that John “was a strong phenomenon, with a lot of rain”.

He had earlier urged people living along the affected coastline to be prepared.

“Seek higher ground, protect yourselves and do not forget that the most important thing is life; material things are replaceable,” he wrote on X.

Authorities in Oaxaca said Monday that they were opening temporary shelters, suspending school classes, closing beaches and mobilizing machinery in case needed to clear roads.

School classes in Guerrero were also cancelled on Tuesday, the state education agency said on X.

The international airport in the tourist resort of Puerto Escondido suspended all flights.

In Guerrero, authorities said around 300 temporary shelters were ready if needed.

Restaurant workers were seen bringing furniture in from beaches, while fishermen returned to shore.

Hurricanes hit Mexico every year on both its Pacific and Atlantic coasts, usually between May and November.

In October last year, Hurricane Otis, a scale-topping Category 5 storm, left a trail of destruction and several dozen people dead after slamming into the beachside city of Acapulco in Guerrero.

Otis rapidly intensified within hours from a tropical storm to the most powerful category of the five-step Saffir-Simpson scale, taking authorities by surprise.