David Johnson, a spokesman for the Washington state Department of Health, confirmed parts of the department's website were hacked Monday morning, with a message similar to what appeared on other municipal sites across the country earlier Monday and on Sunday.
A screen shot provided by the spokesman shows the same Arabic logo and claim that the hack was carried out by "Team System DZ," the same language that appeared on hacked sites in Ohio, Maryland and New York.
All the hacks include the message: "You will be held accountable, Trump, you and all your people for every drop of blood flowing in Muslim countries."
It was not immediately clear who the group purportedly behind the hack is -- or whether it is genuinely affiliated with ISIS.
Johnson said the health department's website was restored within an hour. He said he wasn't aware of law enforcement being contacted over the hack.
The FBI's field office in San Francisco is spearheading a federal investigation into the hacks that happened across the country, a spokesman for the office told CNN.
Ohio: Servers 'taken offline'
The same hack apparently struck several state government websites in Ohio on Sunday, including Gov. John Kasich's official page and the sites of first lady Karen Kasich and the Ohio Department of Rehabilitation and Corrections.
The Ohio sites were back to normal by Monday morning. Kasich's staff members said Sunday they had been working on the Corrections site when they were alerted to their own site being hacked.
In a later statement, Tom Hoyt, spokesman for the Ohio Department of Administrative Services, said all affected servers were "taken offline" and an investigation had been launched to see how the hack had happened.
"We also are working with law enforcement to better understand what happened," Hoyt said.
State Treasurer Josh Mandel posted about the Department of Rehabilitation and Corrections website on Facebook. "Wake up freedom-loving Americans," he said. "Radical Islam infiltrating the heartland."
The FBI's Ohio field office would not say whether Team System DZ was known to them.
Howard County, Maryland
ISIS propaganda content also appeared on the Howard County, Maryland, government website Sunday. The county is in central Maryland, near Baltimore and Washington.
It was restored to normal by Monday morning.
"There was no breach of data and no personal information was compromised," according to a statement from Howard County Executive Allan H. Kittleman. "Howard County government is working with law enforcement agencies and an investigation is underway. We apologize for any inconvenience."
Brookhaven, New York
The official website for the town of Brookhaven, New York, also was hacked, according to Jack Krieger, Brookhaven communications director.
Website visitors saw the same black background and logo found on the other hacked sites, with the same words about being held accountable and blood in Muslim countries.
Town officials took the site down as soon as they learned of the problem and were working Monday morning to restore it to normal.