Kiev, Oct 15 (IANS/EFE): Pro-Russian militias have surrounded more than 100 Ukrainian troops in the eastern town of Lugansk, said Gennady Moskal, the governor of the region, who is loyal to Kiev.

"The situation is critical. Approaching the scene of the fighting is impossible due to continued bombing with heavy artillery deployed by the militants in a wooded area", local agencies quoted Moskal as saying Wednesday.

He added that 112 members of the army and the National Guard had fallen into an ambush in the Bakhmutka area, where the pro-Russian militias have about 20 tanks.

Several soldiers, including a battalion commander and some wounded men, have been captured by the separatists, Moscal reported.

Representatives of the Organisation for Security and Cooperation in Europe had reached an agreement with the separatists to call an immediate ceasefire, but fighting still continues, the governor said.

The local militiamen do not take orders from leaders of the self-proclaimed People's Republic of Lugansk and do not feel obliged to respect a truce as long as Ukrainian troops remained in the area, he explained.

Following several days of relative calm, fighting has intensified in Lugansk and Donetsk coinciding with the appointment of a new Ukrainian defence minister, the former chief of the National Guard, Stepan Poltorak.

Both sides agreed Sep 5 on a ceasefire, which they said has not been completely effective.

Russia has withdrawn its troops from the border with Ukraine ahead of the meeting between the presidents of Ukraine, Petro Poroshenko, and Russia, Vladimir Putin, in Milan, Italy, Friday.