Russian media reports say Uzbekistan has expelled a group of U.S. nationals after accusing them of illegal missionary activities.

The reports Tuesday quote Uzbek officials as saying the Americans, posing as businessmen or English-language teachers, attempted to convert local Uzbeks to Christianity.

Authorities in Tashkent, according to the reports, noted that the Americans had mastered the Uzbek language and went by such Uzbek names as Jahongir, Husan, Jasur and Farhod.

The United States has praised Uzbekistan for its cooperation in NATO operations in neighboring Afghanistan, but has also expressed concern about the former Soviet republic's human rights record.

Two weeks ago, a U.S. grand jury in Alabama indicted an Uzbek national who overstayed his student visa on charges of threatening to kill President Barack Obama.