The Boston Police Department reports a man and woman standing at Washington and Erie streets were surrounded by up to 15 boys and girls, who began beating them when they resisted a robbery attempt around 9:30 p.m. on Monday.

In a statement, police say the two were waiting for a bus, when a girl came up to the woman:

"The female suspect kicked the victim, knocking her into a fence. When the victim attempted to stand up, she was surrounded by a group of approximately 10-15 individuals. At this time, the victim was assaulted again by the female suspect. At this time, a male suspect grabbed her purse and stole several items. The male victim, in an attempt to aid the female victim, intervened allowing the female victim to seek safety at a local market and call police. At this time, the group focused their attention on the male victim, assaulting him as well."

Police say officers quickly found nine of the alleged attackers - all aged between 13 and 16. However, officers on the scene had to radio for reinforcements when some of the other teens returned and tried to break one of those teens out of the cruiser about to bring her to the B-3 station for booking - and then had to chase down a female who swiped the woman's purse, sitting on the sidewalk.

Police say that during booking, one of the females spat in an officer's face.

The alleged attackers face charges of armed robbery, unarmed robbery, assault and battery by means of a dangerous weapon, assault and battery on a police officer causing injuries and disorderly conduct.