Counter-terrorism police are investigating the hacking of a rugby league team website which has been replaced with a page featuring the message: "I love you Isis".
Keighley Cougars website currently shows a black screen with the words "Hacked By Team System DZ" at the top.
A message posted on the club's twitter feed said: "Apologies, the website has been hacked. The developers are working on it. Will let you know when it's back up and running."
A spokesman for West Yorkshire police said they had received a number of calls about the incident.
"We are aware of this incident and have now passed it to our counter-terrorism unit.
"We will work with the club in relation to this and are making enquiries."
A message on the hacked page "to all the population and the government, especially" claims the "State of Islam" is expanding.
The site also features images of fighter jets which it refers to as "warplanes of making America", pictures of the wreckage of "Muslim homes" and bloody images of people injured in fighting.
Posting on social media, one person claimed a host server had been hacked, leading to 60 other websites featuring the same page.
A resident of Keighley expressed concern over the financial details of those who have used the website.
He posted: "Are the bank details of people who have bought season tickets merchandise etc from the online shop safe?"