Malaysia's meteorological department warned today that aftershocks from last weekend's massive quake could generate high waves on parts of the country's northwestern coast and advised people to avoid the sea for the next two days.

The government department said in a statement that since the magnitude 9.0 earthquake off neighbouring Indonesia's Sumatra island on Sunday, a total of 88 aftershocks of between 5.0 and 6.0 on the Richter scale had occurred.

On Friday, seven aftershocks had been detected by early afternoon.

"Aftershocks of the earthquake will continue to occur in the region for several weeks but the likelihood of another major earthquake occurring is low," the department said.

"As there is still a possibility that one of the aftershocks could generate high waves that may affect the coastal areas of Perlis, Kedah and Penang (states) the public is advised to remain alert and refrain from activities in the sea for the next one to two days."

Sixty-six people died in Malaysia in the tsunamis which killed nearly 125,000 people around south and southeast Asia.

While Malaysia lies closer to the epicentre of the earthquake than many countries harder hit, it was protected from the full force of the waves by Indonesia's Sumatra island.