Heavy rains triggered flash floods in the eastern Afghan province of Logar, killing at least 20 people and destroying more than 3,000 homes, officials said Sunday.

The rains lashed several areas of the province on Saturday, injuring more than 30 people in addition to those killed, the provincial governor's office said.

The floods also destroyed dozens of canals and about 5,000 acres of agricultural land, mainly orchards, the statement said, with about 2,000 livestock also killed.

Scores of Afghans die every year from floods and torrential downpours, particularly in impoverished rural areas where poorly built homes are often at risk of collapse.

Security forces and charity organisations were evacuating people to safe areas after their houses were destroyed, the provincial government said.

Government spokesman Bilal Karimi, in a separate statement, urged the international community to provide aid.

"We urgently request the international community... to join hands with the Afghans at this critical time and (to) spare no effort to help the victims," Karimi said.

The country's meteorological department said more heavy rains and floods were expected across 21 provinces in the coming days.

Foreign aid and disaster relief schemes have been dramatically reduced since the Taliban stormed back to power in August last year.

Western nations are wary that any assistance could be commandeered by the Taliban and used to consolidate their grip on Afghanistan.