Three major mountaineering companies joined others in quitting Everest citing fears of violence, safety concerns and tension at base camp, deepening a crisis Thursday on the world's highest peak sparked by the death of 16 guides last week. International expeditions said they were shutting down operations on the mountain, as a Nepalese government delegation was set to fly to Everest base camp to try to cool tensions and save this year's climbing season. Leading US mountaineering company International Mountain Guides said the main route through the Khumbu Icefall, where the avalanche struck a team of guides carrying equipment for their clients, was too dangerous.

By Pavel Polityuk and Alastair Macdonald KIEV (Reuters) - Russian Foreign Minister Sergei Lavrov accused the United States of being behind the political upheaval in Ukraine and said Moscow would respond if its interests came under attack. Lavrov's comments came a day after U.S. Vice President Joe Biden was in the Ukrainian capital with promises of support for the pro-Western government, and a warning to Russia not to interfere in Ukraine. The crisis in Ukraine, now in its fourth month, has dragged Russia's relations with the West to their lowest since the Cold War. In the east, pro-Russian armed separatists have seized about a dozen public buildings and are defying Kiev's authority.

TOKYO (AP) — Showing solidarity with Japan, President Barack Obama affirmed Thursday that the U.S. would be obligated to defend Tokyo in a confrontation with Beijing over a set of disputed islands, but urged all sides to resolve the long-running dispute peacefully.

NEW YORK (AP) — The Prince of Wales and his wife, Camilla, are "utterly devastated" by the death of her brother, who fell outside a hotel bar and suffered a head injury, royal officials said.

By Amy Sawitta Lefevre BANGKOK (Reuters) - Alarmed by the prospect of bloodshed in Thailand as a six-month political crisis nears a critical juncture, former Prime Minister Abhisit Vejjajiva has called for talks between the government and its foes, urging compromise to restore stability. The 49-year-old leader of Thailand's main opposition Democrat Party has joined street demonstrations in Bangkok aiming to force out Prime Minister Yingluck Shinawatra, and his party boycotted a February 2 election, which was nullified by a court in March after widespread disruption.