Hundreds gathered in Kiev 's Independence Square on Sunday to honor the victims of violence that has ravaged Ukraine for months , including 49 people killed when a military plane was shot down . Ukraine President Petro Poroshenko had declared Sunday a day of mourning . The crowd in Kiev observed a moment of silence at noon local time ( 5 a.m . ET ) . `` We bow our heads to the heroes who lost their lives for the sake of their country , to prevent the war from coming into the house of each of us , '' Prime-Minister Arseniy Yatsenyuk said . `` They lost their lives because they defended men and women , children and the elderly who found themselves in a situation facing a threat to be killed by invaders and sponsored by subhumans , '' he said . `` First , we will commemorate the heroes by wiping out those who killed them and then by cleaning our land from the evil . '' The Ilyushin-76 military transport plane went down early Saturday while approaching an airport in the eastern Ukrainian city of Luhansk , said military spokesman Vladislav Seleznyov . Ukrinform said the plane was carrying paratroopers , equipment and food . `` All those involved in the cynical act of large-scale terrorism must necessarily be punished , '' Poroshenko told Ukrinform , the state news agency . `` Ukraine needs peace . Terrorists , however , will receive an adequate response . '' Ukraine 's defense ministry said the plane , which was transporting military personnel , was shot down by insurgents using anti-aircraft machine guns . Ukrinform also said three soldiers were killed Saturday morning near Mariupol . The attack on the plane , which represents one of the bloodiest single events in that nation 's current period of turmoil , spurred a diplomatic flurry to limit further escalation of the crisis . Telephone diplomacy . French President Francois Hollande and German Chancellor Angela Merkel held a telephone discussion Saturday with Russian President Vladimir Putin on the crisis in Ukraine . Hollande and Merkel expressed their deep concern about the ongoing fighting in eastern Ukraine , particularly Saturday 's attack , the Elysee Palace said . The French and German leaders stressed the importance of reaching a cease-fire in Ukraine and avoiding the transfer of fighters and weapons across the Ukrainian-Russian border , according to Hollande 's office . The Kremlin said the three leaders also talked about the drafting of a United Nations Security Council resolution aimed at promoting a settlement . The European leaders stressed the need for an agreement on continuing Russian natural gas deliveries to Ukraine , according to the Elysee . In a phone conversation with Hollande , Poroshenko urged the European Union to immediately consider sanctions against Russia , including the termination of `` military-technical cooperation , '' Poroshenko 's office said . Ukrainian Prime Minister Arseniy Yatsenyuk spoke by phone with U.S. Secretary of State John Kerry , who expressed condolences for the loss of life and `` strong concern '' about the flow of heavy weapons and militants across the border from Russia , a senior State Department official said . Kerry also talked with Russian Foreign Minister Sergey Lavrov , voicing his concern over the downing of the Ukrainian transport plane and pressing Lavrov to `` make clear '' Russia 's commitment to peace , a cease-fire and political dialogue , the state department official said . Video shows plane shot down . In a statement , Poroshenko said the army and state border service had closed 248 kilometers of Ukraine 's border . `` The goal is for us to take back control of Ukraine over the state border and provide adequate response to terrorists , '' he said . Video posted to YouTube claimed to show the plane being shot down . Small flashes can be seen climbing skyward , followed by large flashes on the ground on the distant horizon . The plane was also carrying military machinery and supplies , the ministry said . Officials originally had said the incident occurred late Friday but later updated the time . In an indication of the continued opposition from some quarters to the Kiev government , the state security office said in a statement Saturday that a homemade bomb was found overnight outside a gate to Poroshenko 's office . The device was made of grenades and a kilogram of other material , such as metal screws , and had a threatening note attached that demanded that the President stop military action against the separatists , the statement said . The person who left it was spotted but fled without detonating it . The Kiev-based government is carrying out what it calls an anti-terrorist operation , centered in the Donetsk and Luhansk regions , to try to regain control from pro-Russia separatists . Russia and Ukraine have been engaged in a tense standoff since March , when Russia annexed Crimea and massed troops along its border with Ukraine . Moscow has since begun to withdraw those forces .
Hundreds observe moment of silence in Kiev 's Independence Square . Prime minister of Ukraine will root out the killers . World leaders hold telephone talks with Putin , Russia . The government blames insurgents in eastern Ukraine .