Colonial Pipeline Co on Tuesday said its Line 2 has resumed operations as of midnight, even as it continues to respond to a fire in Shelby County, Alabama, that shut its main lines on Monday.

"Response crews have isolated the fire but access to the site is still limited and our ability to predict a repair schedule is very limited," the company said in a notice to shippers.

Colonial said its schedules are being updated to reflect a Saturday noon restart for Line 1, its main gasoline line, adding that this projection could be changed.

Gasoline futures jumped on Tuesday after the blast.

Colonial, the biggest refined products pipeline system in the United States, is responsible for supplying about one-third of the 3.2 million barrels per day of gasoline consumed on the East Coast, according to U.S. Energy Department data.

A nine-man crew was conducting work on the Colonial Pipeline system in Shelby County at the time of the explosion, according to Alabama Governor Robert Bentley. One person was killed and five others were transported to Birmingham-area hospitals for treatment, Colonial said. The fire has been brought under control, local media reported

The explosion occurred when the crew hit Line 1, its main gasoline pipeline, with a track hoe, Colonial said late Monday.

A source with a large Colonial shipper said they expected the line to likely be down for a minimum of a week while the distillates line will probably be out for at least four days, if there is no damage to it. The distillates line is adjacent to the main line and carries diesel fuel and jet fuel. It was unclear if that line was damaged but it was shut as a precaution.

Analysts at Barclays said the gasoline line could be shut for at least a month because regulators "will be very cautious about restarting the pipelines, especially since Line 1 just suffered a spill and tensions between pipeline companies and environmentalist groups have never been higher."

Gasoline futures for December delivery rose as much as 13 percent early in the session to US$1.6351, its highest since early June. It was up about 10 percent, at US$1.56 per gallon at 9:19 a.m. EDT (1319 GMT).

U.S. gasoline margins soared to the highest levels since early May.

The spill on Sept. 9 led to long lines at the pump and a shortage of fuel in southeastern states like Georgia, Tennessee  and Alabama.

Monday's explosion occurred several miles from the site of a Sept. 9 spill, Colonial said.

Alternative supplies can be hard to come by for inland markets in the southeast United States, which do not have access to ports.

For the northeast, supplies can be relatively easier to get but can be expensive due to the Jones Act, a maritime policy that requires goods transported by water between U.S. ports to be carried on U.S.-flagged ships.

The 5,500-mile (8,850-km) Colonial Pipeline is the largest U.S. refined products pipeline system and transports gasoline, diesel and jet fuel from the U.S. Gulf Coast to the New York Harbor area.