May 27 (Reuters) - A natural gas pipeline in northwestern Minnesota owned by ONEOK Inc's Viking Gas Transmission unit remained shut early Tuesday after exploding early Monday, the 911 coordinator for the Marshall County sheriff's department said.
Jim Duckstad, the 911 coordinator, told Reuters two towns remained without gas Tuesday morning - Warren with about 1,500 residents and Argyle with about 500 residents.
He said Viking told the towns it hoped to restore gas service by Wednesday.
Officials at ONEOK were not immediately available for comment.
Viking Gas Transmission transports gas from Canada from TransCanada Corp's pipeline near Emerson, Manitoba, to serve local natural gas distribution companies in Minnesota, North Dakota and Wisconsin. It terminates at a connection with TransCanada's ANR Pipeline near Marshfield, Wisconsin, according to the ONEOK website.
Viking has a capacity of 0.5 billion cubic feet per day, according to a U.S. Federal Energy Regulatory Commission filing in 2012.
It connects with four major pipeline systems - TransCanada, MidAmerican Energy Holdings' Northern Natural Gas Co and TransCanada's Great Lakes Gas Transmission LP and ANR units.
MidAmerican is a unit of Berkshire Hathaway Inc.
Duckstad said the pipe that exploded was a 24-inch pipe. He said the company was still investigating the cause.
Duckstad said the sheriff's department received a call about the fire at about 6:30 a.m. local time on Monday.
"The fire sent flames up to 100 feet in the air and left a crater that was 15 feet deep," Duckstad said.
He said the company turned the gas off further up the line and it took about two hours for the gas to burn out. The fire was extinguished around 8:30 a.m.
There were no injuries and the six or seven families living within two miles of the site that were evacuated were allowed to return home later Monday morning, Duckstad said.
(Reporting by Scott DiSavino; Editing by Sofina Mirza-Reid)