Three female students at the University of Maryland have reported that they were touched improperly by male strangers about a week ago as they slept, authorities said.

All the assaults occurred early Sept. 9, authorities said, two of them off campus and one in a residence on the College Park campus. All three sites are within a few hundred yards of each other.

U-Md.’s Public Safety Department said the on-campus incident, in particular, was unusual but unsettling.

Two assaults were first reported Friday in Public Safety Department campus alerts.

No injuries were reported in the incidents, which were reminiscent of assaults reported over several years, through 2010, on or near the Georgetown University campus.

One of the Maryland incidents occurred between 4 and 5 a.m. as a student slept in her off-campus residence in the 7500 block of Rhode Island Avenue, police said. They said she woke to feel someone touching her.No sign of forced entry was found, police said..

Authorities said the other off-campus incident occurred between 2:30 and 5 a.m. in the 4700 block of College Avenue, in a room where the student and her boyfriend had gone to sleep after a party.

She woke, authorities said, to find “an unknown male touching her back and buttocks.” She alerted her boyfriend, and the intruder left.

In the third incident, the student was sleeping in her apartment in the Leonardtown complex on campus when she was awakened after 3:30 a.m. by someone touching her torso and breasts, authorities said. It was not known how he entered the apartment.

In the Rhode Island Avenue incident, the intruder was described as white and dark-haired. In the College Avenue incident, the intruder was described as white, about 20 years old and 180 pounds, with short dark hair and wearing a dark shirt and dark pants.The third intruder was described as having curly hair and a striped shirt.