The peak of Russian holiday shopping was disrupted in a St. Petersburg retail chain on Monday when two of the chain’s stores were struck by bombs that released foul-smelling gas. At least 77 people were made ill by the odor, none seriously, the authorities said. The police said the gas appeared to be a form of mercaptan, a group of malodorous compounds, often with an intense sulfuric smell, that include a form commonly added to odorless natural gas to make fuel leaks detectable. The gas in the bombs, while capable of producing an almost unbearable odor, was largely harmless, they said. Full Story