The incident took place at a dairy farm in the central German town of Rasdorf on Monday.
A roof was damaged and one of the 90 cows was injured, according to Reuters.
Gas explodes with flames
High levels of the gas had built up from the flatulence and belches of cows. A static electrical charge ‘caused the gas to explode with flashes of flames,’ police said in a statement.
One cow was treated for burns.
Cattle naturally emit methane during digestion. In the US, cattle emit about 5.5m metric tons of methane each year into the atmosphere, accounting for 20% of US methane emissions, according to the US Environmental Protection Agency.
Globally, ruminant livestock (mammals which chew cud, such as cows, goats and sheep) produce about 80m metric tons of methane annually.