Floods and landslides brought about by torrential rain in Indonesia's North Sumatra province have killed at least 28 people by Thursday, with rescue efforts hampered by what an official described as a "total cut-off" of roads and communications.

A rare tropical cyclone blew across Indonesia's Sumatra island, inundating the nearby Malacca Strait and causing floods and landslides, the country's meteorological agency said on Wednesday. 

Another 10 people were still missing, Abdul Muhari, spokesperson for the country's disaster mitigation agency, said on Thursday.

Up to 8,000 people across North Sumatra have been evacuated from their homes and roads remain blocked by landslide debris, with aid and logistics now being distributed via helicopter, Abdul said.

The regions of Sibolga and Central Tapanuli were among the hardest hit, said Yuyun Karseno, an official at the agency's North Sumatra division, adding that communications and power had been cut off.

"There is no more access, due to a total cut-off," Yuyun said when asked about the rescue efforts. "Until now we can't communicate with folks in Sibolga and Central Tapanuli."

Among the dead were one family in Central Tapanuli, Indonesia's search and rescue agency said. 

Flooding also impacted the provinces of West Sumatra and Aceh, authorities said.

More flooding is expected in several other Sumatran provinces, including Aceh and Riau, over the next two days, the meteorological agency said, citing extreme weather.

Copied