The clashes, which come on the eve of a regional security body meeting and against the background of fighting between Russia and Ukraine as well as Azerbaijan and Armenia, started after Kyrgyz border guards accused the Tajiks of taking positions at a part of the border that has not been demarcated.

Both Kyrgyzstan and Tajikistan are allied with Russia and host Russian military bases, but fighting over border issues is frequent and last year almost resulted in an all-out war between the former Soviet republics.

The Tajik side said in a statement Kyrgyz border guards opened unprovoked gun and mortar fire on their outpost.

Tajikistan’s border force said one border guard was killed in the incident and another two were injured, the RIA Novosti news agency reported.

Kyrgyzstan said two of its servicemen were wounded and that another exchange of fire took place in a different border area.

Kyrgyz and Tajik leaders are expected to attend a summit of the Shanghai Security Organisation in Uzbekistan this week alongside Russian president Vladimir Putin and Chinese leader Xi Jinping as well as a host of other world leaders.