A powerful magnitude-6.3 earthquake followed by strong aftershocks in western Afghanistan on Saturday, the country's national disaster authority said.

The death toll from strong earthquakes that shook western Afghanistan has risen to 2,000, said a Taliban spokesman on Sunday, in one of the deadliest earthquakes to strike the country in two decades.

The update also said 465 houses had reportedly been destroyed and a further 135 were damaged.

"Partners and local authorities anticipate the number of casualties to increase as search and rescue efforts continue amid reports that some people may be trapped under collapsed buildings," the UN said in a statement.

Four villages in the Zenda Jan area of Herat province experienced the brunt of the quake and aftershocks, according to disaster authority spokeswoman Mohammad Abdullah Jan.

According to the US Geological Survey, the quake's epicenter was around 40 kilometers (25 miles) northwest of Herat. It was followed by three powerful aftershocks with magnitudes of 6.3, 5.9, and 5.5, as well as minor shocks.

(With input from AP)