Four Yale students were the victims of multiple street crimes this past weekend, one of which was severe enough to land its victims in the hospital.

In his first campuswide e-mail reporting street crime since the end of August, Yale Police Department Chief James Perrotti addressed the University on Monday, detailing three separate incidents, including robberies, aggressive panhandling and assault.

Two undergraduates were treated for injuries late Saturday night after being attacked with milk crates while they were being robbed, Perrotti said. Neither of the other two victims suffered injuries in their separate robberies, he said. Many Yale students said they were not particularly alarmed by the crimes, but some said they now see the need to exercise caution when outside at night.

According to Perrotti’s alert, the most severe of the crimes occurred at 11:15 p.m. Saturday, when a group of four to five male teenagers surrounded two Yale seniors who were walking near Howard Avenue and Spring Street. The teenagers — who then assaulted and robbed the students — were described in Perrotti’s e-mail as under five feet five inches tall.

Both students, who declined to comment for this article, suffered injuries as a result of the attack and were treated for lacerations following the assault, Perrotti said. The YPD could not be reached for comment.

In a second incident that took place closer to central campus, a graduate student at the corner of College and Wall streets was reaching for money to give to a panhandler when the woman grabbed the student’s wrist and took the money from her hand, according to the e-mail. The student was not injured as a result of the “aggressive panhandling incident,” which occurred earlier Saturday evening.

“The woman who took the money is approximately 5’2” tall, has dark acne marks on face and was wearing loose pants or skirt and a red turban,” Perrotti said in his alert. “Fortunately, there were no injuries reported.”

Early that morning, three men robbed another graduate student on the corner of Church and Center streets on the edge of campus. The victim was not injured during the robbery, Perrotti said.

At the end of his message, Perrotti said he wanted to remind students to be careful and use campus security resources when outside at night.

Many students said that while they were surprised by the detailed description of the milk crate incident, they were not particularly alarmed by the robberies.

“I don’t feel any less safe,” Travis Nelson ’08 said. “[Crime] is just part of life here.”

Other students agreed that they were not upset by the e-mail and will not change their habits as a result.

Stefan Weijola ’11 said the e-mail did not change his impression that street crime is not a major concern.

“I’ve walked around alone before and never had anything like that happen,” he said. “After this incident, I’m probably still going to walk by myself.”

Some students said they still feel generally safe around campus, but because of the alert, they see the need for more personal safety awareness.

Kate Bowden ’11 said the nature of the crime alarmed her.

“Because the [violent] incident didn’t occur all that close to campus, it doesn’t make me feel that much less safe,” she said. “But the fact that a violent crime occurred should be a good reality check for us.”

Several students said they think students should use “common sense” when going outside at night in the wake of this weekend’s incidents.

Perrotti sent his last community alert detailing a street crime on Aug. 29 after a graduate student was assaulted on Prospect Street near Hillside Place. Under federal law, he is required to send campuswide alerts when there is the possibility of a continuing threat.