The U.S. Department of State said a joint Georgian-Russian monitoring of the Roki Tunnel, linking breakaway South Ossetia with the Russia’s North Ossetian Republic was needed to curb illegal arms trafficking.

It has also called for “an immediate halt to violence” in the South Ossetian conflict zone and for direct talks between the parties.

The South Ossetian side said six people were killed and fifteen injured on its side as a result of the most intensive fire in the region in years on August 1 and overnight on August 2. The Georgian side said one Georgian policeman and six Georgian civilians were injured.

“[We] understand that the OSCE is investigating the incident and we’re going to look forward to their report,” Gonzalo R. Gallegos, the Department of State’s acting deputy spokesman said on August 4.

“These incidents underscore the need for an immediate increase in the number of OSCE monitors in South Ossetia, as well as joint Georgian-Russian monitoring of the Roki Tunnel to stem the flow of illicit arms, ammunition, and armed groups into the region,” he added.