Daesh said in a statment they target the citizens of the coalition countries,” a statement by the group said.

There are no previously known terrorist attacks on foreigners in Tajikistan.

Earlier on July 30, Interior Minister Ramazon Rahimzoda said in Dushanbe that a governmental group had been formed to investigate the incident, in which two Americans, one Dutchman, and a Swiss citizen were killed.

At least three other foreigners -- including one French citizen -- were injured in the July 29 incident, in the Danghara district of the Khatlon region, about 150 kilometers south of the capital.

Authorities said at least one person had been detained in connection with the attack and one other was killed in a confrontation with security forces. That contradicted earlier reports suggesting two suspects had been killed and several more detained.

Three young men were named by police and are being sought in connection with the attack.