Hurricane Oscar has weakened to a tropical storm after making landfall on Sunday in eastern Cuba.

The US National Hurricane Center said Oscar made landfall as a Category 1 hurricane on Sunday evening.

The storm is forecast to weaken further as it moves north of Cuba towards the south-eastern and central Bahamas.

The hurricane centre in Miami said the storm’s centre arrived in the Cuban province of Guantanamo, near Baracoa, on Sunday evening.

People illuminated by headlights
The storm added to problems caused by a massive power blackout (AP)

Its maximum sustained winds were near 80 miles per hour.

The system is expected to move across eastern Cuba on Sunday night and Monday.

Forecasters said 15.2 to 30.5 centimetres of rain are expected across eastern Cuba by Wednesday with some isolated locations getting up to 45.72 centimetres.

A storm surge of up to three feet in some areas of Cuba’s north shore was possible, the centre said.

Rain and some flooding have been reported in low-lying areas of Cuba’s eastern provinces. Cuban media reported high swells on the coast and some damage to buildings in Baracoa.

Oscar made landfall on Great Inagua island in the Bahamas earlier on Sunday.

The hurricane’s arrival comes as Cuba tries to recover from its worst blackout in at least two years, which left millions without power for two days last week. Some electrical service was restored on Saturday.

Philippe Papin of the National Hurricane Centre said it was somewhat unexpected that Oscar became a hurricane on Saturday.

“Unfortunately the system kind of snuck up a little bit on us,” Mr Papin said.

Hours earlier Tropical Storm Nadine formed off Mexico’s southern Caribbean coast.

It degenerated into a tropical depression as it moved over land.