As it had been reported earlier, one Chinese national was killed and four others injured in a cross-border attack in Tajikistan's south on November 18. 

Sources told Radio Liberty’s Tajik Service on the same day that the attackers crossed from Afghanistan.  But it was unclear if they were criminals possibly involved in drug trafficking, a crime that is common in the area, or members of a militant group.

The Chinese nationals were reportedly working at a gold mine in the Zarbuzi Gorge, Shamsiddin-Shohin district in Khatlon province.

The Shamsiddin-Shohin district shares a porous border with Afghanistan that is often crossed by smugglers and militant groups.

Although the Taliban has assured neighboring countries that Afghan territory will not serve as a base for terrorist activities, Tajik authorities have been on high alert in recent years.

Significantly, the November 18 attack marked the first known incident resulting in the death of a Chinese national in Tajikistan, home to major Chinese-funded energy and transport projects.

The deadly attack underscored the persistent security concerns along Tajikistan's common border with Afghanistan.  Dozens of extremist groups are active inside Afghanistan, including the Islamic State-Khorasan (IS-K), the Islamic Movement of Uzbekistan (IMU), and Jamaat Ansarullah, which is comprised mainly of Tajik citizens.

Meanwhile, the Collective Security Treaty Organization (CSTO) heads of state on November 28 signed a resolution endorsing the CSTO Targeted Program on Strengthening the Tajik-Afghan Border.  

The program includes three stages and is designed for five years. At the first stage, it is planned to clarify the details.  On the one hand, the Tajik side is to submit suggestions to strengthen certain stretches of the border.  On the other hand, the CSTO member nations should determine physical and other resources that can be allocated to protect Tajikistan's state border.   This stage is expected to take about a year.  Within a five-year period, it will be followed by the second and third stages offering the implementation of particular measures to develop this border.

According to RFE/RL’s Tajik Service, Edward Lemon, a Central Asia expert at Texas A&M University, says China has long been concerned over the security of its operations in Tajikistan and it has invested significantly in bolstering the Tajik military and law enforcement.

"Rather than derailing China's investments in the country, I think this attack will only strengthen China's role in security in the country," he said.  "We can expect further military aid, training, and potentially an expanded role for Chinese private security companies operating in the country to protect Chinese investments."