Two Kurdish football teams playing in the Iraqi Premier League have withdrawn from all remaining fixtures after opposition fans likened their clubs to the Islamic State (IS).

Erbil Sports Club and Zakho Football Club are the only two Kurdish teams that compete in the Iraqi league and have usually done so without incident.

However, after Erbil players were the targets of derogatory chants during the club's game against Iraqi side Najaf on Friday (16 December), both Kurdish clubs have confirmed their withdrawal from the league.

Fans were chanting "Peshmerga is Isis" and "Erbil is Isis", Erbil's communication officer Rebin Ramzi said to the Kurdish news outlet Rudaw.

Footage of the game shows the players refusing to play during the second half when the chants were heard. Heated exchanges could then be seen between Erbil players, coaches and Fifa officials, who tried to defuse the situation.

After some time, the game was resumed again and eight minutes of stoppage time was added.

Ramzi said that Erbil's coaches told the players to continue playing to "save their lives", indicating that their lives would have been in danger if they had done otherwise, reported Rudaw.

After the game ended one-nil in Najaf's favour, Najaf fans were seen storming the field.

Najaf, south of Baghdad, is considered one of Iraq's holiest cities and is made up by a majority of Shi'ite Muslims. Local news outlets have reported that the area's cemeteries have "swelled" with the deaths of fighters who have fought against IS (Daesh) in Mosul and other cities.

Ramzi said representatives from Erbil and Zakho met after the game and decided to withdraw from the Iraqi league, adding that he believes there was no other way for Kurdish clubs to stop the defamatory remarks.

In a statement, the Iraqi Football Association (IFA) decried the language used by some of Najaf team fans, reported Asharq al-Awsat.

"These phrases negatively impacted the country and reflected a foreign culture that contradicts with the history of Iraq," added the statement.

The IFA said it would seek to impose tough penalties regarding such behaviour in the future, to prevent it from occurring again.

"We apologise to Erbil management, players and fans," added the IFA statement.

Ramzi added that management from Najaf have apologised to Erbil, and would send a delegation in person to the club to apologise in person.

IBTimes UK has contacted Fifa for comment, but no one was available.