ANKARA, April 20 (Xinhua) -- A Turkish Cup semifinal between two of the country's biggest clubs was abandoned amid unprecedented chaos on Thursday, after the Besiktas coach was struck by an object thrown from the stands, an incident that shows violence is still common in Turkish football stadiums despite police efforts.

Senol Gunes needed five stitches and was taken out on a stretcher with a possible concussion and was kept overnight in a hospital. He was later discharged on Wednesday morning but will still have to receive further treatment.

According to witnesses quoted by the local press, it was a metal object that hit the manager on the head, prompting riot police to storm the pitch and send the players to the dressing room.

There are also reports and footage on social media showing Fenerbahce officials attacking Besiktas staff members in the tunnel near the changing rooms.

At the time of the abandonment the score was 0-0 and the tie was poised at 2-2 on aggregate. The match is likely to be replayed, with the Turkish Football Federation set to make a decision in the coming days.

The Turkish press commented that there would be severe punishments for Fenerbahce but also possibly for Besiktas as well.

The incident followed a series of vocal disagreements between Fenerbahce fans and players on the Besiktas bench sparked by the dismissal of Besiktas' Portuguese defender Pepe.

Istanbul derbies are often tempestuous affairs and the clash between Besiktas and Fenerbahce last September saw five red cards and 12 yellows.

The incident adds to tensions as the Turkish league season heads to its climax, with all four big Istanbul sides - Besiktas, Fenerbahce, Galatasaray and Basaksehir - all in contention for the title.

The Turkish Football Federation (TFF) now has to make a decision about the outcome of the match.

Following the incident, Besiktas President Fikret Orman voiced his dismay at the violent incidents calling it "a sad day for Turkish football. Derbies are always tense but still we never experienced an incident of this proportion."

He also accused Fenerbahce security staff of attacking members of his entourage.

For their part some Fenerbahce fans accused Senol Gunes of "acting like a Hollywood star" in order to have the referees suspend the game and blame Fenerbahce for the aggression.

Turkey is no stranger to violence in stadiums. Turkish authorities have implemented stricter rules inside and outside stadiums across the country.

In the past three decades, hooliganism has become a real problem in Turkey where football is undoubtedly the sport of the masses.

Last year, Turkish President Recep Tayyip Erdogan, who was a football player in his youth and a keen football fan, stepped in to organize a meeting where concerned parties have discussed additional measures against football hooliganism.

The Turkish leader said he learned much from the game in terms of discipline, teamwork and loyalty.

Since then, sensitive matches are subjected to a greater security analysis ahead of time, with the authorities providing several levels of risk assessment.

Special police task forces are also monitoring provocations made on social media.