At least 12 people died and 25 were injured in the attack in Iraq
Real Madrid players will wear black armbands for their away game against Deportivo on Saturday as a mark of respect after a group of their fans were massacred in Iraq.
At least 12 people died and 25 were injured after Islamic State fighters launched a gun and grenade attack on a cafe where the club's supporters had gathered, reports say.
It is thought about 50 supporters of the Spanish club were at the premises in Balad, a town 50 miles north of Baghdad, to meet for coffee and watch re-runs of the side's previous matches.
The militants, disguised in security uniforms and armed with assault rifles, were said to have carried out the atrocity because they "don't like football and think it's anti-Muslim".
Ziad Subhan, president of the Real Madrid supporters' club in Balad, was quoted by the website AS.com as saying: "A group of Islamic terrorists, from ISIS, came into the cafe, armed with AK-47s, shooting at random at everyone who was inside."
When asked about the motives for the attack, he said: "They don't like football, they think it's anti-Muslim.
"They just carry out attacks like this. This is a terrible tragedy."
In a statement, Real Madrid said it "deeply regrets the terrible attack in Iraq...expresseses its great sadness and offers its regards and condolences to the relatives and friends of the victims".
"Real Madrid extends all of its solidarity to the people of Iraq, who suffer the excessive injustices of extreme violence," the club said.
"The Real Madrid players will wear black armbands tomorrow (Saturday) as a sign of their mourning and respect."
At least three gunmen opened fire at around midnight at a cafe in the predominately Shia Muslim town, where young men had gathered to start the weekend.
The attackers then fled and several hours later three of them reportedly set off their explosive vests at a market after being cornered by police and Shia militia. Two others are thought to be on the run.
IS said in a statement that three suicide attackers targeting Shia militiamen had detonated their explosives.
Meanwhile, Ammar Hekmat al Baldawi, a deputy governor of Salaheddin province, said: "A group of armed men from Daesh (IS) disguised in security forces uniforms attacked a cafe in Balad at around midnight, using grenades and gunfire.
"They blew themselves up when the security forces and some residents chased them and got close."