Iran has sentenced two internationally renowned Iranian AIDS physicians to six and three years in prison for their alleged participation in a US-backed plot to overthrow Iran's Islamic regime, their lawyer said Thursday. The attorney, Masoud Shafii, said authorities notified him this week of the sentences handed to the two physicians and brothers. Arash and Kamyar Alaei were convicted over the weekend of allegedly taking part in a US-backed plot to overthrow Iran's authorities. The lawyer said he would appeal. The prosecution of the Alaei brothers raised an outcry among international human rights groups. Two other unnamed persons were sentenced with the doctors but their identities or length of prison terms were unknown.