Military officials are warning that al-Qaida fighters in northern Afghanistan are massing close to the border with Tajikistan and might attempt to cross the border.
Reuters news agency quotes a Tajik border guard official as saying the country has doubled the number of Russian and Tajik troops guarding the eastern border.
Reports say al-Qaida fighters have been regrouping in the border area because they have bases in Tajikistan and Kyrgyzstan leftover from 1999 and 2000.