COLOMBO, Dec 8 (Reuters) - Sri Lanka ordered a countrywide recall of cooking gas cylinders on Wednesday after hundreds of unexplained explosions and fires in recent weeks which have injured several people, including about 60 such explosions last Thursday. Gas cylinders are a common source of energy for cooking in the tropical island nation, especially in rural areas. The Consumer Affairs Authority ordered Litro Gas, which holds a roughly 80% market share, to recall all unused cylinders issued before Dec. 4. It said that the recalled cylinders would be replaced by ones bearing a red and white seal for easy identification. It was not immediately clear whether the second gas company Laugfs has received a similar order. One explanation for the explosions put forward by experts is a change in the gas mix introduced earlier this year which may have raised pressure in the cylinders, causing more leaks. The gas companies have denied this and instead blamed faulty regulators and dilapidated stoves. But the government has ordered the two gas companies to revert to a 70:30 butane and propane mix, from the 50:50 mix the companies switched to this year. Last month, President Gotabaya Rajapaksa named an eight-member committee to probe the explosions. read more The CAA has also ordered the gas companies to add the pungent ethyl mercaptan to the gas cylinders to make it easier to smell gas leaks. The use of LPG stocks imported before the end of November has also been prohibited.