A company that operates a major U.S. energy pipeline says it was forced to temporarily halt all pipeline operations following a cybersecurity attack.

In a statement, Colonial Pipeline said the attack took place Friday and also affected some of its information technology systems. The company describes itself as the largest refined products pipeline in the United States. It says it’s responsible for transporting more than 100 million gallons of fuel daily, through a pipeline system spanning more than 5,500 miles between Texas and New Jersey.

The Alpharetta, Georgia-based company said it hired an outside cybersecurity firm to investigate the nature and scope of the attack and has also contacted law enforcement and federal agencies.

FILE - In this Sept. 20, 2016 file photo vehicles are seen near Colonial Pipeline in Helena, Ala.  A major pipeline that transports fuels along the East Coast says it had to stop operations because it was the victim of a cyberattack. Colonial Pipeline said in a statement late Friday that it “took certain systems offline to contain the threat, which has temporarily halted all pipeline operations, and affected some of our IT systems.” (AP PhotoBrynn Anderson, File)

FILE - In this Sept. 20, 2016 file photo vehicles are seen near Colonial Pipeline in Helena, Ala. A major pipeline that transports fuels along the East Coast says it had to stop operations because it was the victim of a cyberattack. Colonial Pipeline said in a statement late Friday that it “took certain systems offline to contain the threat, which has temporarily halted all pipeline operations, and affected some of our IT systems.” (AP PhotoBrynn Anderson, File)

“Colonial Pipeline is taking steps to understand and resolve this issue,” the company said in a late Friday statement. “At this time, our primary focus is the safe and efficient restoration of our service and our efforts to return to normal operation. This process is already underway, and we are working diligently to address this matter and to minimize disruption to our customers and those who rely on Colonial Pipeline.”

The precise nature of the incident was unclear, including who launched the attack and what the motives were.

The FBI and the White House’s National Security Council did not immediately return messages seeking comment. The federal Cybersecurity Infrastructure and Security Agency referred questions about the incident to the company.

A hacker’s botched attempt to poison the water supply of a small Florida city raised alarms about how vulnerable the nation’s critical infrastructure may be to attacks by more sophisticated intruders.

Anne Neuberger, the Biden administration’s deputy national security adviser for cybersecurity and emerging technology, said in an interview with The Associated Press in April that the government was undertaking a new effort to help electric utilities, water districts and other critical industries protect against potentially damaging cyberattacks. She said the goal was to ensure that control systems serving 50,000 or more Americans have the core technology to detect and block malicious cyber activity.

Since then, the White House has announced a 100-day initiative aimed at protecting the country’s electricity system from cyberattacks by encouraging owners and operators of power plants and electric utilities to improve their capabilities for identifying cyber threats to their networks. It includes concrete milestones for them to put technologies into use so they can spot and respond to intrusions in real time. The Justice Department has also announced a new task force dedicated to countering ransomware attacks in which data is seized by hackers who demand payment from victims in order to release it.