21.   Investigators have said that flames from a small stove started the fire.

22.   Investigators have said that flames from a small stove started the fire in one of the carriages, which spread to other cars.

23.   It was believed to have started in a small stove used to heat the building, the officials said.

24.   Scientists suggest switching to small stoves that burn natural gas, which is plentiful and clean.

25.   Speculation has centered on the possible explosion of gas cylinders or small stoves passengers bring aboard trains to cook meals, despite regulations forbidding it.

26.   Suspicion has focused on small stoves and gas cylinders passengers often carry onto trains to heat meals and water for tea or coffee.

27.   Suspicion focused on gas cylinders and small stoves passengers often bring aboard to cook meals, despite regulations forbidding it.

28.   Suspicion focused on the gas cylinders and small stoves passengers often bring aboard to cook meals, despite regulations forbidding it.

29.   The spartan cell had only a mattress on the floor and a small wood stove and a few pieces of wood by its side.

30.   They cook on a small stove heated with a natural gas canister.