Kyrgyz and Tajik border guards have exchanged fire along the Central Asian states' disputed border, leaving one Kyrgyz soldier dead and another wounded in an incident each side blamed on the other.
Each side also offered differing casualty estimates of the other.
The skirmish follows bigger clashes in April along another disputed segment of the Kyrgyz-Tajik border that left more than 50 civilians and border guards dead.
The violence has raised fears of a wider conflict between the post-Soviet neighbors.
Tajikistan's National Security Committee blamed the Kyrgyz side for the latest incident, saying four Kyrgyz border guards "illegally" crossed the border near the Devashtich district. It said the four were dressed in military and civilian clothes, had Kalashnikov assault rifles, and intended to steal nine horses.
"Kyrgyz border guards, contrary to the warning of the Tajik border guards about violation of the state border line, opened fire on them. Two Kyrgyz border guards were wounded by the return fire of Tajik border guards," the committee said in a statement published by the Khovar state media outlet.
Kyrgyzstan's National Security Committee confirmed the exchange of fire, but gave a different account.
It said a Kyrgyz border unit was patrolling on horseback when it was attacked by Tajik border guards in the Leilek district of the Batken region.
The Kyrgyz side has also suggested there were dead and injured among the Tajiks involved, although Dushanbe has not confirmed any casualties.
Almost half of the 970-kilometer Kyrgyz-Tajik border has not been demarcated, leading to repeated tensions since the two former Soviet countries gained independence three decades ago.