Several government websites in the US states of Ohio and Maryland had to be shut down Sunday after being hacked to display messages supporting the Islamic State group.
Among the affected websites was one belonging to Ohio Governor John Kasich.
Posted on the websites was a message from a group calling itself Team System DZ, vowing revenge against US President Donald Trump.
"You will be held accountable Trump, you and all your people for every drop of blood flowing in Muslim countries," it read, adding: "I Love Islamic state."
The messages were written in gold lettering against a black backdrop.
The hacked websites also displayed the Muslim profession of faith written in white lettering in Arabic, proclaiming that "there is no god but Allah and Muhammad is the prophet of Allah."
The message posted on Kasich's website also played an Islamic call to prayer.
A website for Howard County, Maryland, several miles outside Washington DC, was also affected.
Some of the websites remained out of service early Monday, while Kasich's www.governor.ohio.gov site was back up and running after being taken offline Sunday.