MANCHESTER - Two men robbed a woman of a restaurant's night deposit and, when a witness chased after them, one pulled out a knife and told him to back off, police said.

The incident happened about 9:30 pm. Tuesday at the Mall of New Hampshire. The night manager at Arby's told police two men came up behind her as she walked toward her parked vehicle. One pulled her purse from her shoulder and fled with it.

The woman chased after him but could not catch him.

As he ran, the robber took out the cash deposit and then tossed the purse.

A 21-year-old bicyclist witnessed the robbery and began following the men, who ran from the mall to South Willow Street. As the bicyclist got closer, one of the men turned and brandished a knife, warning the witness not to follow them.

The witness backed off but tried to keep the men in sight, losing them in the area of Goodwill and John Devine Drive.

The robbers are described as white men in their 20s, of average height and build. Both had short dark hair and wore dark, hooded sweatshirts and pants. One of them also wore a green ski mask.

Anyone with information about the robbery is asked to call police at 668-8711. Anonymous tips for cash rewards may be made through Manchester Crimeline at 624-4040 or online at manchestercrimeline.org.