BISHKEK -- Uzbek authorities have started digging trenches in the disputed areas along the Kyrgyz-Uzbek border, RFE/RL's Kyrgyz and Uzbek services report.
Uzbek officials say the major goal of the trenches is to prevent aliens from coming onto Uzbek territory.
Kyrgyz authorities say they are concerned by Tashkent's decision to dig the trenches.
Kyrgyz border guard officials told RFE/RL that neither the Uzbek nor the Kyrgyz side is permitted to undertake any type of construction or engineering works along the border until it is fully delimited.
The Uzbek-Kyrgyz border was not fully marked after the collapse of the Soviet Union in 1991 and many parts of it are disputed.
On May 26, a group of armed individuals attacked police in the Uzbek cities of Khanabad and Andijon near the Kyrgyz border.
Uzbek officials say the group entered Uzbekistan from Kyrgyzstan, which has a large population of Uzbeks in its southern part.
Kyrgyzstan denies the accusations.