TEHRAN - The United Nations refugee agency said it had begun repatriating Afghan refugees from Iran's southern border crossing on Saturday after an earlier return program was held up by fighting between local Afghan warlords.

"At least 405 refugees have returned to Afghanistan today and we are expecting more returnees because of the calm situation in the area," UNHCR spokesman Mohammad Nouri told Reuters.

Skirmishes north of the town of Zaranj, capital of the southwestern Afghan Province of Nimruz, forced the UNHCR to halt a planned return of refugees to the area in April and concentrate on the northern crossing to the Province of Herat.

Forces loyal to Zaranj warlord Abdolkarim Barahui clashed with those of Jalil Nourzai from Farah Province to the north in early April, but the fighting has since died down, Nouri said.

Iran is home to an estimated two million Afghan refugees who have fled more than 20 years of civil war in their homeland.

Some 27,000 Afghans have so far returned home with the help of the UNHCR in the last month through the northern border crossing near the Afghan town of Islam Qala.

Many more refugees have returned by their own means since the strict Taliban was toppled from power by a coalition of Afghan and U.S.-led forces late last year.

The UNHCR said it was planning to open a third border crossing between Islam Qala and Zaranj to speed up repatriations.