At least 48 people were killed and 356 others injured as strong earthquakes and ensuing tsunami rattled Indonensia's Central Sulawesi province on Friday, a disaster agency official said on Saturday.

Three shallow quakes of 6.0, 7.4 and 6.1 magnitude struck off the central province and triggered a tsunami of 0.5 to 3 meters in coastal areas near Talisa beach of Dongala district, and bay city of Palu, the provincial capital, the meteorology and geophysics agency said.

All victims have been rushed to hospitals, spokesman of the national disaster management agency Sutopo Purwo Nugroho said.

The spokesman said the casualties were only counted in Palu, the provincial capital of Central Sulawesi, and the victims in Donggala district including the coastal areas near Talisa beach were not included in the figure.

"Accordingly, the death toll and injuries as well as the damage will likely to climb," he told a press conference.

Most victims of the powerful 7.4-magnitude quake, Sutopo said, were hit by debris and falling blocks of concretes.

A tsunami triggered by the quake devastated buildings and residential areas in the coastal areas, he said, adding that the specific damage was still unknown as the risk assessment was underway.

Earlier, local media quoted hospital staff as saying that at least 30 people were killed in the earthquake and tsunami hitting Palu.

Soldiers, police, disaster management agency personnel and volunteers were evacuating the quake and tsunami victims, said spokesman Sutopo.

Power outage has cut off local communications which is hampering the relief efforts.