Three Saskatoon firefighters accused of assaulting a police officer and obstructing justice say they were only play fighting when they were stopped by police last summer.

The incident happened in the early morning of Aug. 12 when two police officers who were on patrol saw four men walking on the Broadway Bridge. The officers said one of the men jumped on another from behind and knocked him to the ground.

Police intervened and ordered the men to stop fighting, and that's when the situation escalated.

Taking the stand in court Monday Const Christine Talloden said the off-duty firefighters claimed they were only play fighting.

Talloden told court the pair were throwing punches, that it did not look like playing, and they did not stop after being ordered to several times.

She one of the men grabbed her partner from behind in a bear hug.

That's when Talloden said called for backup because she feared for the safety of her partner.

Under cross examination the lawyers for the three firefighters questioned the officers' memory of the incident as well as some mistakes and details left out of their reports.

The courtroom was packed with fellow firefighters and others on Monday

Two more police officers are expected to take the stand Tuesday, after which the defence will call its witnesses. Lawyers did not say if any of the accused will take the stand.