PROVIDENCE — The police are investigating several robberies that occurred in recent days, including the gunpoint mugging of a student on the Brown University campus in which one of the attackers left a shoeprint on the face of the student.

Ethan Curren, 19, of 27 Brown St., was walking on the campus behind a building at 182 George St. shortly after 1 a.m. Friday when he was set upon by a group of young males, according to the city and university police. One man approached him on the pretext of asking directions to Thayer Street, but he then pressed a handgun to Curren’s neck.

Curren said he was told to “take off everything,” but that he punched the gunman in the face. The group then attacked him en masse, he told the police, and he was knocked to the ground and struck numerous times.

His assailants stole his wallet, which contained $80 to $100 and credit cards, a knife and his backpack, which contained a cell phone and textbooks. The books later were recovered in Cranston.

Curren suffered cuts and bruises and a possible bone fracture. He was treated at Rhode Island Hospital.

The university Department of Public Safety issued a crime alert to the Brown community and reiterated its longstanding advice about walking after dark. The alert said, in part: “The intent of most criminals is to target individuals who appear vulnerable, isolated and preoccupied. Initiating conversation, such as asking for directions or money, is often a tactic used by criminals to create an opportunity for an assault or robbery.”

Other incidents that are under investigation are:

•A purse-snatching at about 4:30 p.m. Sunday in the parking lot of the Super Stop & Shop supermarket, 850 Manton Ave., Manton. Lindsey Procaccini, 32, of Cranston, said she was approaching her parked car when someone in another car reached out and grabbed her pocketbook. Procaccini clung to the pocketbook and as the car dragged her a short distance, she suffered cuts and scrapes on her hands, knees and hip before she lost her grip, the police said. The pocketbook contained her wallet, cell phone and medication. Procaccini was treated at Roger Williams Hospital.

•An attempted robbery at about 5 p.m. Sunday in the vicinity of Greeley and Charles streets in the North End. Cerenia Augosto, 46, of 48 Opper St., which is near Greeley and Charles, said she was coming from a friend’s house when a man wearing a mask accosted her with a gun and demanded money. Augosto ran to her house and the would-be robber got nothing, according to the police. Officers later arrested Ryan Martin, 18, of Cranston, and he was charged with assault with intent to rob.

•A robbery and carjacking at about 5:30 p.m. Sunday on Jenkins Street, Mount Hope. Matthew Bevilacqua, 18, of 106 Jenkins, told the police that he was a passenger in a car and that a man with a gun tucked into his waistband ordered Bevilacqua and the driver, identified only as Calvin, out of the car. The robber took Bevilacqua’s cell phone and keys and stole the car. Neither the man identified as Calvin, nor the vehicle could be located, the police said.