People look through the front windshield of a damaged trolleybus in Donetsk, January 22, 2015. At least seven civilians were killed on Thursday when a shell or a mortar hit a trolleybus stop in the rebel-controlled city of Donetsk in eastern Ukraine, a Reuters witness said. The Reuters cameraman said he saw six bodies on the ground near, and inside, a trolleybus in a southern district of the city. Windows of shops nearby had been blown out by the blast. (Photo by Alexander Ermochenko/Reuters)

A passenger killed when a trolleybus was damaged by a mortar shell is seen inside the bus in Donetsk, eastern Ukraine, Thursday, January 22, 2015. A new peace initiative for Ukraine began taking shape as mortar shells rained down Thursday on the center of the main rebel-held city in the east, killing at least 13 people at a bus stop. The civilian death toll has been mounting steadily in the conflict between Ukrainian troops and Russian-backed separatists that the United Nations says has killed more than 4,700 people since April. (Photo by Igor Ivanov/AP Photo)

Passengers killed when a trolleybus was damaged by a mortar shell are seen in interior of the bus and outside, left, in Donetsk, eastern Ukraine, Thursday, January 22, 2015. (Photo by Igor Ivanov/AP Photo)

A view shows a damaged trolleybus in Donetsk, January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

A Ukrainian military vehicle goes down the street on Independence Square in Kiev, Ukraine, Friday, January 23, 2015. Hours after a new peace initiative for Ukraine began taking shape, mortar shells rained down Thursday on the center of the main rebel-held city in the east, killing at least 13 people at a bus stop. (Photo by Sergei Chuzavkov/AP Photo)

A woman walks past a damaged building near a trolleybus stop in Donetsk, January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

Prisoners of war (POWs), representing Ukrainian armed forces and escorted by members of the armed forces of the separatist self-proclaimed Donetsk People's Republic, kneel down on the ground as they visit a public transport stop, where civilians were earlier killed on Thursday, in Donetsk, January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

Prisoners of war (POWs) from the Ukrainian armed forces, are escorted by members of the armed forces of the separatist self-proclaimed Donetsk People's Republic, as they visit a public transport stop, where civilians were earlier killed on Thursday, in Donetsk, January 22, 2015. An artillery shell or mortar struck a public transport stop in the rebel-controlled city of Donetsk in eastern Ukraine on Thursday, killing at least eight civilians in an incident which both sides blamed on the other. (Photo by Alexander Ermochenko/Reuters)

Prisoners of war (POWs), representing Ukrainian armed forces and escorted by members of the armed forces of the separatist self-proclaimed Donetsk People's Republic, line up as they visit a site near the public transport stop, where civilians were earlier killed on Thursday, in Donetsk, January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

Prisoners of war (POWs), representing Ukrainian armed forces and escorted by members of the armed forces of the separatist self-proclaimed Donetsk People's Republic, get out of a truck as they visit a site near the public transport stop, where civilians were earlier killed on Thursday, in Donetsk, January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

Members of the armed forces of the separatist self-proclaimed Donetsk People's Republic drive a tank on the outskirts of Donetsk January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

A woman makes prisoners-of-war (POWs), who are representing Ukrainian armed forces and escorted by members of the armed forces of the separatist self-proclaimed Donetsk People's Republic, kneel down on the ground at a site near the public transport stop where civilians were earlier killed on Thursday, in Donetsk January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

Members of the armed forces of the separatist self-proclaimed Donetsk People's Republic drive an armoured vehicle on the outskirts of Donetsk January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

Members of the armed forces of the separatist self-proclaimed Donetsk People's Republic drive a tank on the outskirts of Donetsk January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

People lean out of windows to look at a Grad multiple rocket launcher system of the armed forces of the separatist self-proclaimed Donetsk People's Republic at a site near the public transport stop, where civilians were earlier killed on Thursday, in Donetsk January 22, 2015. (Photo by Alexander Ermochenko/Reuters)

Local people inspect the place of the explosion near of a bus stop in downtown of Donetsk, Ukraine, 22 January 2015. At least nine people were killed and nine injured early 22 January when a grenade exploded at a bus stop in the Ukrainian city of Donetsk, pro-Russian separatists said. (Photo by Alexander Ermochenko/EPA)

A general view of the kindergarten No9 which was shelled in Debaltseve, Donetsk area, Ukraine, 22 January 2015. The violence in eastern Ukraine surged again amid reports that government troops had given up Donetsk airport after months of fighting against pro-Russian separatists. A report and videos published by Russia's Komsomolskaya Pravda newspaper said that the Ukrainian armed forces had left the airport's main terminal and that separatists had captured 16 soldiers. (Photo by Anastasia Vlasova/EPA)