MOSCOW (Reuters) - About 1,000 Russian troops have started a month-long exercise in Tajikistan, a week after concluding the previous drills, Interfax quoted officials from Russia's central military district as saying on Tuesday.

       Russia has stepped up military activity and reinforced its base in Tajikistan as U.S.-led forces have pulled out of neighbouring Afghanistan and the Taliban taken over.

       (Reporting by Olzhas Auyezov; editing by John Stonestreet)