A Chinese citizen was killed in an attack by armed assailants on workers on the Tajik-Afghan border, local sources told the media.

Four Chinese citizens and a Tajik citizen were wounded in the attack in the Zarbuz Gorge of the Shamsiddin Shohin district in the Khatlon region.

According to informed sources, the attack took place on November 18. The Chinese nationals who were targeted in the attack were working in a gold mine in the area.

A local source told the news website Yeni Safak, "All the victims have been taken to a hospital in the district. Security forces are present at the scene of the incident and an investigation is underway."

The attackers are said to have come to Tajikistan from Afghanistan and targeted Chinese engineers and workers.

However, it is not yet officially clear whether the attack was carried out by drug traffickers or Islamist militant groups.

The Tajik government has not yet officially commented on the incident.

The incident could raise concerns about the infiltration of armed and militant groups into Central Asian countries. Previously, Baloch militants in Pakistan have carried out bloody attacks on Chinese engineers and workers.

Tajikistan has always expressed concern about the security situation on the Afghan border and has asked the Shanghai Cooperation Organisation and the Collective Security Treaty Organisation to strengthen security measures on the border.

In the past three years, there have been numerous reports of drug traffickers and extremist groups attempting to cross the Tajik border. After the Taliban's return to power in Afghanistan, Tajikistan has stepped up border security measures and deployed more troops in these areas.

One of the most serious threats to Tajikistan is the Ansarullah group, which is based in northern and northeastern Afghanistan, especially in Badakhshan. The group, which is allied with the Taliban, is an Islamist opponent of Tajik President Emomali Rahmon.

On August 6 last year, Tajikistan's State National Security Committee announced that it had eliminated three members of the Ansarullah group. In the past, they had transported large shipments of weapons, ammunition, explosives, communications equipment and financial resources to Tajikistan, it said.