DUSHANBE/BISHKEK (Reuters) - Two Tajiks were killed in a border shootout between Tajikistan and Kyrgyzstan, the bloodiest clash so far this year on the frontier between the former Soviet neighbors, officials said on Tuesday.

Tajik police said gun fire from Kyrgyzstan on Monday evening had killed a border guard and one civilian and wounded four other civilians.

The Kyrgyz border force blamed the incident on Tajikistan, saying Tajik servicemen had tried to erect a border post "on an undelimited part of the border" and started to destroy a bridge across a river used by Kyrgyz citizens.

"The calls of the Kyrgyz border guards not to destroy the bridge and to remove the border post were met with stones thrown by Tajik nationals. Then Tajik border guards were the first to open fire," the Kyrgyz border guards said in a statement.

There were no reports of any casualties on the Kyrgyz side during the half-hour shootout.

The incident, in a remote part of the fertile but overpopulated and impoverished Ferghana Valley, was only the latest to show border tensions between Central Asia's two poorest nations.

Along with Uzbekistan, also located in the Ferghana Valley which lies on a drug trafficking route out of Afghanistan, the three mainly Muslim countries are due to take part in a summit of the Shanghai Cooperation Organisation, a security and economic cooperation pact led by Beijing and Moscow.

Oil-rich neighbor Kazakhstan will be the sixth participant at the summit, to be held in the Tajik capital Dushanbe next month.

Tajik Deputy Prime Minister Murodali Alimardon was due to travel to the Kyrgyz capital Bishkek on Tuesday to try and defuse the tension, Tajik police said. The Kyrgyz foreign ministry said it had handed a note of protest to Tajikistan about the incident.

Kyrgyzstan says it has registered a total of 31 incidents on its 970-km (600-mile) border with Tajikistan since the beginning of this year, including three when firearms were used.

As borders remain largely unmarked after the Soviet Union's collapse, villagers often clash over land, water and pastures, confrontations that sometimes involve the use of weapons by border guards.


(Writing by Dmitry Solovyov; Editing by Robin Pomeroy)