Government websites in Ohio, Maryland and New York have been hacked with what appears to be pro-ISIS propaganda.
On Sunday, visitors to governor.ohio.gov were greeted with a black background and an Arabic symbol while an Islamic call to prayer played in the background.
"You will be held accountable Trump," text on the landing page said, "you and all your people for every drop of blood flowing in Muslim countries."
"I Love Islamic state," it said.
A group calling itself Team System DZ apparently hacked Gov. John Kasich's official site, along with the sites of first lady Karen Kasich and the Ohio Department of Rehabilitation and Corrections. Those pages displayed the same message that Kasich's did. In addition to the pro-ISIS language, a line appeared on each page that said "Hacked by Team System DZ."
Ohio: Servers 'taken offline'
It was not immediately clear who the group is -- or whether it is genuinely affiliated with ISIS. 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.