As part of its monitoring remit, the OSCE uses Unmanned Ariel Vehicles, sometimes called drones. Between being shot at and forced to land, they record military activity from both sides, in and around the front line. This activity can be either military vehicles such as tanks and artillery, along with heavy weapons seen firing.

A good example of this, is the two tanks seen below.
Spotted on Jan 25th and breaching the Minsk 2 Agreement (which Russia has signed), these are Russian led forces T-64 tanks. Positioned right on the front line, the knock on effect of this, will probably see Ukraine moving up its own tanks or heavy weapons, to repel any possible firing from these tanks.

Obozne - Location of Russian tanks on Ukraine's frontline 2

The tanks were located near the small village of Obozne, in the Luhansk Oblast (province). From behind the Siverskyi Donets River, Ukrainian forces cover the area on three sides. The “LPR” reference seen on the OSCE graphic, indicates the Russian controlled, Luhansk People’s Republic.

Obozne - Location of Russian tanks on Ukraine's frontline 1

Written by Glasnost Gone

Just a British chap who doesn't like murdering dictators who go topless.