The State Committee for National Security said that at 3 a.m. local time the 20 attackers struck the post on the border with Uzbekistan, located 60 kilometers southwest of Dushanbe in the Rudaki district. The attackers were said to have come from neighboring Afghanistan.

The IS group did not confirm it was behind the overnight assault. The militants have claimed previous attacks in Tajikistan.

Fifteen "unknown armed masked" attackers were killed by return fire, while the remaining five attackers were captured, the committee said.

During the attack, the unidentified persons captured five Kalashnikov assault rifles, it said.

The Interior Ministry reported that four vehicles of the attack group were also destroyed.

At least one of the attackers was a woman, according to unconfirmed reports.

RFE/RL correspondents were not allowed to approach the scene. All roads in the area have been closed and armed checkpoints have been set up in other parts of the country, including in the capital.

The committee's Central Border Guard Directorate said the group had entered Qabodiyon district in Tajikistan's Khatlon region from the Qalai-e Zal district of Afghanistan's Kunduz Province on November 3.

The border post attacked by the group was manned by a unit of the Sultanabad border-guard detachment.

No further information was provided about the attackers and the names of the dead police officer and border guard.

The IS group claimed responsibility for an attack that killed four Western cyclists in southern Tajikistan in July 2018 and for two deadly prison riots in November 2018 and May 2019.

The latest incident took place on Tajikistan's Constitution Day, a national holiday, and as President Emomali Rahmon was on an official trip to Europe accompanied by two dozen ministers until November 12.