Voters in Uzbekistan are casting ballots to decide if President Islam Karimov should be allowed to extend his term of office for two years. The former Communist Party boss has been in power since 1990, when Uzbekistan was a Soviet republic. He was elected president by popular vote the following year, after the fall of the Soviet Union.

Two years ago Mr. Karimov was re-elected with more than 92 percent of the vote in a ballot that was criticized by the international community as being neither free nor fair. Sunday's referendum proposes to extend the president's term from five to seven years. His current term expires in 2005.

Critics charge that Mr. Karimov has routinely suppressed free speech and jails his political opponents. The Uzbek leader rejects the criticism. Nevertheless, the referendum is expected to be adopted easily, because the 63-year-old president is seen by many voters as a source of political stability in Uzbekistan.

Mr. Karimov has gained added international stature with his public support for the U.S.-led military campaign in neighboring Afghanistan. But some human rights organizations, such as the New York-based Human Rights Watch say President Karimov believes that his support for Washington's war on terrorism has made him immune to criticism from the West.

About 1,500 U.S. troops are based in Uzbekistan and a bridge in the southern part of the country provides a vital link to transport aid and supplies to neighboring Afghanistan.

Since the military campaign in Afghanistan began last fall, a number of high-ranking U.S. officials have visited. Last week General Tommy Franks was in the capital, Tashkent, and Secretary of State Colin Powell met there with Mr. Karimov last December.

Initial results of the referendum are expected Monday.