Kolkata/Siliguri, July 23 -- The toll from a tunnel explosion in south Sikkim's Namchi district rose to 22 on Wednesday with rescuers retrieving 10 more bodies from the under-construction facility of the Teesta Stage-VI Hydel Project, officials said adding that thee remained missing. The incident took place on Monday when a methane explosion killed at least 12 and trapping many others. At least 25 workers were working inside Adit-3 of the 15-km long tunnel, connecting the barrage at Siwarni with the powerhouse at Tarkhola in South Sikkim. Rescuers and officials present at the site said that most of the bodies had burn injuries. Rescuers, who went inside the tunnel with breathing apparatus looking for trapped survivors, described the tunnel as pitch-dark, hot, full of poisonous gases and muddy. They had to wear Self-contained Breathing Apparatuses, weighing around 15 kilograms. "Conditions are very bad inside. It is pitch-dark and hot inside. The tunnel is full of poisonous gases such as methane and carbon monoxide. The floor of the tunnel is full of mud," said a member of the rescue team of Coal India Limited. "We have recovered 10 bodies on Wednesday. The death toll is 22. At least three people are still missing. Rescue teams from the NDRF and Coal India Limited are still working at the site," said Sonam D Bhutia, Namchi superintendent of police. Migrant workers from West Bengal, Jharkhand, Punjab, Assam and Uttarakhand were among the deceased, police said. One dead worker was a resident of Sikkim. Members of the CIL rescue team claimed to have spotted at least eight bodies inside the tunnel on Tuesday. The Namchi district administration could not verify the claims till Wednesday evening. "The high levels of carbon monoxide and methane is in the tunnel are making it difficult to work," said an official working at the site. People aware of the developments said that the search and rescue operations had to be suspended for some time because water and mud had accumulated at the site. It, however, resumed after a few hours. "We have deployed earth movers. Our engineers are repairing the damaged pipes so that water and mud could be pumped out and rescuers could go in," said an official....