Rescuers searching a coal mine rocked by a methane gas blast found the bodies of several more victims Tuesday, bringing the death toll to 104 a day after Russia's deadliest mining disaster in a decade. Some 200 workers were in the Ulyanovskaya mine in the coal-rich region known as the Kuzbass at the time of the blast, which occurred early Monday at a depth of around 270 meters (885 feet), emergency and regional officials said. Emergency officials put the death toll at 104, while six others were still missing; 93 had been rescued earlier. At one point they had said there were 106 confirmed deaths, but later revised the figure without explanation. Company officials and safety experts, along with a British citizen and his interpreter, were in the mine examining a British-made hazard monitoring system just before the blast occurred, said Sergei Cheremnov, a spokesman for the regional government in Kemerovo where the mine is located. The British man and the interpreter were killed, and regional governor Aman Tuleyev said about 20 top mine staff including the chief engineer were among the dead. A British employee of the British-German mining consultancy IMC, Ian Robertson, was in the mine at the time of the blast, said Sergei Nikishichev, an official at the company's Moscow office. Robertson's job involved evaluating reserves, Nikishichev said, but he could not say exactly what Robertson was doing in the mine at the time. President Vladimir Putin sent Tuleyev a telegram asking him to convey his sympathy for relatives of victims and support for the injured survivors, and said he was ordering a thorough investigation of the accident, according to the Kremlin. The massive mine in the city of Novokuznetsk, about 3,000 kilometers (1,850 miles) east of Moscow, is operated by Yuzhkuzbassugol, an affiliate of Russian coal and steel company Evraz Group SA, which acquired a 50-percent stake in the company in 2005. No one answered repeated calls to the company. However, company spokesman Eduard Sivtsov earlier told Russian television channel NTV that rescuers were checking a large section of the mine for survivors. "Their work is complicated by a great number of obstructions," he said. President Vladimir Putin ordered Emergency Situations Minister Sergei Shoigu to travel to the area, and the industrial regulatory agency Rostekhnadzor had sent investigators. The incident was the latest to highlight the precarious and hazardous state of Russia's mining industry, which fell into disrepair when government subsidies dried up after the Soviet collapse. At least 30 workers died in Russian mining accidents last year, including 25 who perished in a fire at a Siberian gold mine. In 2004, a blast at a mine on the outskirts of Novokuznetsk killed 47 workers - the deadliest in the region since 1997, when a methane explosion at a mine in the city killed 67.