A Ferghana Valley border clash this weekend yet again highlights the potential for violence in Central Asia’s most densely populated and ethnically diverse region.

Several hundred residents of the Uzbek enclave of Sokh reportedly attacked a Kyrgyz border post and took Kyrgyz citizens hostage on January 5 and 6, according to local news wires. Sokh (also spelled Soh) is an island of territory controlled by Uzbekistan and entirely surrounded by one of Kyrgyzstan’s poorest provinces, Batken.

Though Sokh is populated mostly by ethnic Tajiks, a minority in both countries, the episode is an unsettling reminder of the fighting between ethnic Kyrgyz and Uzbeks in southern Kyrgyzstan that left hundreds dead in 2010.

From Radio Free Europe:

The incident started during the afternoon of January 5 when Kyrgyz border guards were overseeing the installation of power lines to the newly constructed border post near the village of Charbak.

Residents of the Soh enclave village of Hoshyar reportedly attacked the guards and the post.

Kyrgyz border guards fired into the air to disperse them.

On January 6, a group of residents from Soh returned and took six residents of the village of Charbak back into Soh as hostages.

At least seven others were captured while driving through the Uzbek enclave when the unrest broke out.

Russia's Interfax news agency cited witnesses to the events as saying, "At the start there were more than 100 people (Uzbek citizens) but their numbers grew…"

Kyrgyzstan's newspaper "Vecherny Bishkek" early January 7 reported the crowd eventually numbered more than 1,000 people.

The Uzbek citizens reportedly tried to seize weapons from the Kyrgyz border guards.

AKIpress reported several Kyrgyz border guards were injured in the clashes.

The Ferghana Valley is a patchwork of poorly defined and disputed borders between Kyrgyzstan, Tajikistan and Uzbekistan. Fights over land and water resources are common, as is smuggling. Making life even more complicated, Soviet-era highways disregard contemporary borders, meaning residents are often hostages to the whims of unfriendly border guards.

On Sunday, a day after the initial clash, Sokh residents reportedly took a Kyrgyz bus and its passengers hostage, and torched several Kyrgyz cars. Some reports say Kyrgyz citizens are amassing on the border to stage a rescue, which would likely lead to further conflict.

The weekend episode follows the January 4 shooting death of a Kyrgyz smuggler by Uzbek border guards. Last July, Bishkek and Tashkent traded blame for a deadly shootout that left a border guard on each side dead.