Following a bench trial, defendant was convicted of two counts of resisting or obstructing a police officer in the act of preserving the peace, MCL 750.479; MSA 28.747, and one count of trespassing, MCL 750.552; MSA 28.820(1). Defendant was sentenced as a second felony offender to two to three years imprisonment and ninety days in jail respectively. Defendant appeals as of right. We affirm.

Defendant first argues that at the time of the assault the officers were not acting as police officers, but were agents of a privately owned establishment. Therefore, the evidence was insufficient to support his conviction for resisting or obstructing a police officer. We disagree. While the officers were working as security guards at Burger King at the time of the assault, the City of Kalamazoo had authorized the hiring of officers to serve in such off-duty capacities by the private sector. The officers were in full uniform of the Kalamazoo Police *183Department and witnessed defendant commit a breach of the peace by trespassing. Consequently, they had a duty to act as police officers. When reviewing this evidence in a light most favorable to the prosecution, we cannot say that the trial court was unjustified in finding that the officers were acting as police officers when defendant assaulted them. People v Petrella, 424 Mich 221, 268-270; 380 NW2d 11 (1985).

Defendant next contends that, in order to support a conviction for trespass, the prosecutor was required to prove that defendant was given an opportunity to leave the premises but refused. However, our review of the record indicates that defendant was charged with trespassing after his entry was forbidden. Under this type of trespass, refusal to leave is not a necessary element. See MCL 750.552; MSA 28.820(1). There was sufficient evidence supporting defendant’s conviction.

Affirmed.