OSCE Special Monitoring Mission (SMM) in Ukraine has reported that the situation in the central-southern part of the Luhansk region and the central part of the Donetsk region remained volatile.

"There were reports of heavy fighting in and around Luhansk city. Other parts of the country remained calm," reads the latest report from the SMM in Ukraine posted on its Web site.

The mission said that there was a reported movement of a significant amount of military hardware across the Russian-Ukrainian border.

"A senior military Ukrainian officer speaking to the SMM on 13 July, stated that a column of tanks and other military hardware had entered Ukraine from the Russian Federation at the Zelenopillia border crossing point on that day," the OSCE mission said.

The officer claimed that the artillery pieces and trucks, captured in a video image, were not issued to the Ukrainian army.

'The column, according to the military officer, was later seen in Luhansk city and was on the move, in the direction of Donetsk city. The SMM is currently not in a position to verify this information, but will follow up," the observers stressed.

Moreover, on July 12, the observers went to the town of Kramatorsk, and learned that pensions and salaries have been paid, electricity and gas were provided. However, the water supply had not been restored.

"The situation in Donetsk city remained tense. According to media, in the southwest suburbs there was fighting, involving heavy artillery," the SMM reported.

There were armed individuals and groups in camouflage on the streets in the Petrovsky district of Donetsk.