The OSCE renewed its call Wednesday for the "immediate and unconditional release" of its officials taken hostage in Ukraine's restive eastern region, where troops are clashing with pro-Russian forces.

Two groups of observers from the Organization for Security and Cooperation in Europe (OSCE) -- totaling eight international monitors and a Ukrainian interpreter -- have been held captive and incommunicado since separatists picked them up, three days apart, in late May.

Republican Sen. Lindsey Graham has said the U.S. must spend money to help Lebanon confront the Syrian refugee crisis as the U.S. Senate appropriators advanced a $48.3 billion budget for foreign aid and State Department work.

The Appropriations foreign operations subcommittee adopted the budget by consensus Tuesday. The full committee examines it Thursday.

A blast hit a major Ukrainian pipeline on Tuesday, but did not appear to affect the transport of Russian gas to European clients, Ukrainian officials said.

The incident occurred one day after Russia halted gas deliveries to Ukraine over unpaid debts, sending only the quantities purchased by European clients.

Moscow on Tuesday condemned the killing of a Russian state television reporter in Ukraine's separatist east, accusing Kiev of "unleashing terror" against Russian journalists.

Russia's Investigative Committee said it had opened an investigation into Igor Kornelyuk's death, while the foreign ministry demanded that Ukraine follow suit.

Russian Foreign Minister Sergei Lavrov on Tuesday urged the OSCE to put pressure on Ukraine to implement a roadmap for de-escalating the violence drawn up by the pan-European security body.

"Ukrainian leaders absolutely refuse to implement the (de-escalation) roadmap and we call all countries members of the Organization for Security and Cooperation in Europe to put pressure on Ukrainian leaders," Lavrov told reporters in the Serbian capital.

The United Nations said Monday 34,000 Ukrainians have been forced to leave their homes as a violent pro-Russian insurgency rages in the east of the country.

The U.N. said it had identified 19,000 displaced people in Ukraine, while estimates from local authorities indicated another 15,000 had been forced from their homes in areas it does not monitor.

The world needs to take a harder line on Russia after its annexation of Crimea, a Ukrainian minister said Monday at an international conference in Tokyo.

The two-day meeting involving Asian countries and members of the Organisation for Security and Co-operation in Europe comes as tensions flare between the West and Moscow over Ukraine, where pro-Russian forces are fighting against regular troops.

Europe risked gas supply disruptions Monday after Russia rejected an 11th-hour compromise deal and cut supplies to Ukraine in a feud that has further fractured East-West relations.

Ukraine hosted the last-gasp talks hoping to keep an energy shortage from compounding the problems of the new pro-Western leaders as they confront a two-month separatist insurgency threatening the very survival of the ex-Soviet state.

Urgent EU-brokered gas talks between Russia and Ukraine resumed in Kiev on Sunday ahead of a looming threat by Moscow to cut off its neighbor's supplies in a move that could impact Europe, an EU source told Agence France Presse.

Russia's RIA Novosti news agency cited its own source as saying that the first meeting involved EU Energy Commissioner Guenther Oettinger, Ukrainian Prime Minister Arseniy Yatsenyuk and Alexei Miller, the head of Russia's state gas firm Gazprom.

Russian Foreign Minister Sergei Lavrov claimed Sunday that a Ukrainian mob that attacked Moscow's embassy in Kiev wanted to take over the compound and see "blood spilled."

"Our diplomats feel that the attackers wanted to physically seize the embassy," news agencies quoted Lavrov as saying. "There are also reasons to believe that they wanted to see blood spilled."