Russia's Winter Olympics officially got underway on the Black Sea coast on Friday with a burst of fireworks and a dazzling opening ceremony that President Vladimir Putin hoped would dispel fears of militant attacks and a row over gay rights.
Putin has staked his reputation on hosting a safe and successful Games in the resort town of Sochi, where a high-octane show before 40,000 spectators at the gleaming new Fisht Stadium signalled the start of the full sporting programme.
He was joined by leaders from China, Japan and about 40 other countries in a show of support despite an international outcry over Russia's "gay propaganda" law passed last year, which critics say curtails the rights of homosexuals.
U.S. President Barack Obama, French President Francois Hollande, British Prime Minister David Cameron and German President Joachim Gauck are not attending the Games, and the U.S. delegation includes openly gay representatives.
Despite grumblings about poor accommodation and tight security, the mood among competitors and officials after a handful of early qualifying events in Sochi and at the mountain base 40 km (25 miles) to the northeast was upbeat.
"Conditions offered to the athletes are absolutely outstanding," said French Olympic Committee president Denis Masseglia on a clear, crisp day.
Some 37,000 security personnel are on high alert over threats by Islamist militant groups based in the nearby north Caucasus region to attack the Feb. 7-23 Games, the most expensive ever staged at an estimated cost of $50 billion.
Separatist guerrillas seeking an independent Islamic state in Chechnya and neighbouring regions of southern Russia have vowed to disrupt the Olympics, which they say are taking place on land seized from Caucasus tribes in the 19th century.
Despite a "ring of steel" around venues, Russian forces fear a woman suspected of planning a suicide bombing may have slipped through.
Security analysts believe that an attack is in fact more likely elsewhere in Russia to humiliate Putin, who launched a war to crush a Chechen rebellion in 1999.
Twin suicide bombings killed at least 34 people in December in Volgograd, 400 miles (700 km) northeast of Sochi.
Moscow mayor Sergei Sobyanin on Friday tweeted to people in the capital "to be especially vigilant and careful on the metro, on ground transportation, at train stations etc." now that the Games were about to begin.
Underlining international unease over the threat of violence, the U.S. Transportation Security Administration is temporarily banning carry-on liquids, aerosols, gels and powders on flights between