US meteorologists warn that Hurricane Otis is becoming an “extremely dangerous” Category 4 storm as it approaches the Pacific coast of southern Mexico.

According to the National Hurricane Center (NHC), the storm’s winds have now reached 145mph (233km/h).

By early Wednesday, Otis is expected to be a Category 5 storm with “potentially catastrophic” results.

Acapulco, a popular resort area, is at risk of damaging waves and heavy flooding, according to the National Hurricane Center.

According to the NHC’s latest bulletin at 00:00 GMT on Wednesday, Otis was 85 miles south of Acapulco.

The state of Guerrero has issued a hurricane warning for a 350km stretch of coastline between Zihuatanejo and Punta Maldonado.

There is a potential for life-threatening coastal flooding near and to the east of where the storm makes landfall as a result of a potentially catastrophic storm surge.

According to the NHC, the surge will be accompanied by large and destructive waves near the coast.

In Guerrero and western coastal areas of Oaxaca state, Otis was expected to produce up to 15 inches (38 cm) of rain on Friday.

As a result of landfall, the NHC also forecast that “rapid weakening will occur”.

Guerrero’s authorities have prepared emergency shelters ahead of the hurricane’s arrival.

There have also been cancellations of school classes across the state.

The beach area in Acapulco has been patrolled by soldiers.