* Russia opens new power plant in Tajikistan
* Seeks to retain regional influence
By Roman Kozhevnikov and Anastasia Onegina
SANGTUDA, Tajikistan, July 31 (Reuters) - Russia opened a large hydroelectric plant in Tajikistan on Friday as part of its push to counter growing U.S. clout in ex-Soviet Central Asia.
Control over Central Asia's abundant oil, gas, metals and hydro resources is at the centre of Russia-U.S. rivalry, particularly at a time when escalating fighting in nearby Afghanistan in adding to security concerns in the region.
Tajikistan has been particularly courted by Washington in recent months because of its role as a transit nation for U.S. troops fighting the Taliban in neighbouring Afghanistan.
Seeking to boost Moscow's weight in a region Russia sees as part of its sphere of influence, President Dmitry Medvedev flew to Tajikistan to open a new $720 million power plant due to account for 12 percent of Tajikistan's electricity output.
"(Sangtuda-1 plant) is a large project that will link our countries and peoples for many years," Medvedev said, speaking at the giant Soviet-style construction perched on a powerful river gushing down the Pamir mountains.
Security remains a major concern in the region which has been rocked by a series of violent clashes between state troops and armed gangs described as Islamist rebels by the authorities.
On the eve of Medvedev's visit to Sangtuda, a bomb blew up a police car in the Tajik capital Dushanbe, injuring a policeman.
The power plant deal cements Moscow's role as Tajikistan's key partner at a time when the West is taking steps to forge closer ties with ex-Soviet republics -- a process Moscow sees as an attempt to poach its long-standing allies.
The United States last month convinced Kyrgyzstan, another Central Asian nation, to allow U.S. troops to keep a military air base in the country.
In another case, Uzbekistan, Central Asia's most populous nation also bordering Afghanistan, has strongly objected to Moscow plans to set up a new military base in Kyrgyzstan and threatened to block any such moves, according to Russian media.
Relations with Tajikistan itself have also been rocky. The tiny nation has irked Russia by drafting a new law limiting the use of the Russian language and promoting Tajik, a language closely linked to Farsi. (Writing by Olzhas Auyezov; editing by Maria Golovnina)