SLOVYANSK, Ukraine — Gunfire and blasts have been heard around an eastern city in Ukraine that has become the focus of an armed pro-Russian insurgency.
An emergency siren sounded in Slovyansk at dawn Friday in a further indication government troops assayed a military assault.
Vyacheslav Ponomarev, the insurgency-appointed mayor of Slovyansk, said self-defense forces had shot down two helicopters and taken one pilot hostage. He said no Ukrainian troops could be seen in the city. Details could not be independently confirmed.
An APTN cameraman reported seeing black plumes of smoke on the edge of the city.
The armed element of the insurgency is focused on Slovyansk, a city 160 kilometers (100 miles) west of Russia in which seven European observers from the Organization for Security and Cooperation in Europe remain held by pro-Russia gunmen.