WASHINGTON (AFP) — Buffalo Bills safety Damar Hamlin collapsed on the field after suffering a cardiac arrest during Monday night's game against the Cincinnati Bengals and is in critical condition in hospital, his team said.

"Damar Hamlin suffered a cardiac arrest following a hit in our game against the Bengals," the Buffalo Bills said on their Twitter page.

"His heartbeat was restored on the field. He is currently sedated and listed in critical condition," the Bills said.

The seriousness of Hamlin's condition was immediately obvious as his teammates gathered around him during treatment, with many of them kneeling to pray and some openly weeping.

Hamlin took a hard hit to the chest as he tackled the Bengals' Tee Higgins during the first quarter of the match, stood up and then collapsed to the ground. Medical staff rushed onto the field to treat him.
He received medical attention for more than 30 minutes before being taken from the field in an ambulance.

The National Football League, one of the most violent team sports, has been dealing with growing concerns in recent years over concussion injuries for players from hits to the head.

During the treatment, the crowd in Cincinnati remained silent and television coverage broke away from the scene on the field.

ESPN commentator Joe Buck said medical staff had been "pounding" on Hamlin's chest and it was quickly clear from the reaction of the players that the situation was grave.

ESPN also said the 24-year-old Hamlin was provided with oxygen and that his family, watching the game, joined him in the ambulance.

The Bills confirmed ESPN reports that Hamlin had received cardiopulmonary resuscitation on the field, adding that he was taken to the University of Cincinnati Medical Center for further testing and treatment.

Early reports suggested the game would restart after a five-minute warm-up, prompting an outpouring of anger on social media.

But the two teams' coaches conferred with referees and the players were told to head to the locker room with the game "temporarily suspended."

The NFL had earlier said Hamlin was in critical condition and that league commissioner Roger Goodell had announced the game's postponement.

"Our thoughts are with Damar and the Buffalo Bills. We will provide more information as it becomes available," the NFL said.

"The NFL has been in constant communication with the NFL Players Association which is in agreement with postponing the game," it said.

ESPN analyst Booger McFarland, a former NFL player, called for the league to abandon the game during the tense wait while Hamlin was being treated on the field.

"Nobody is concerned about football right now one. They are concerned about one thing, the health and safety of this young man," he said.