This is stated in the weekly report of the OSCE Mission published on the Web site of the organization on Thursday.
"The mission continues to monitor a large number of people in uniform who are crossing the border in both directions (from Russia to Ukraine and vice versa)," the report reads.
In particular, during the reporting period of November 20-26 the mission observed 590 people (mostly men, and 10 women) dressed in military uniforms.
"These people have crossed the border independently or in groups of three to 10 people. The Monitoring Mission noted that during this period there were more groups than usual," the report read.
Observers also said they saw several "cossacks" identified by fur caps and markings. Cossack groups from Russia have been involved in the seizure of several towns in the districts of Luhansk and Donetsk regions held by militants.
As UNIAN reported earlier, on November 26 Advisor to the Chairman of the Security Service of Ukraine Markiyan Lubkivsky said that there are around 7,500 Russian troops deployed in the so-called Donetsk and Luhansk Peoples’ Republics.