One student was shot in the right hand and three others were robbed at gunpoint in two separate incidents early Sunday morning.

Theodore Delong DRA ’07, a 27-year-old graduate student, was shot in the right hand during an attempted robbery near the intersection of Dwight and Elm streets. He was taken to the Hospital of Saint Raphael for treatment. Yale Police Department Chief James Perrotti said Delong was not seriously injured.

The New Haven Police Department responded to the shooting at 12:55 a.m., NHPD spokeswoman Bonnie Winchester said, and were told by Delong that the assailant was a man riding a bicycle.

In the second incident, two females and a male were approached by three men on bicycles at 2:18 a.m. on Lake Place, behind Payne Whitney Gymnasium, while walking home to Ezra Stiles College, University Police Lt. Michael Patten said.

“One of the men pointed what they thought was a gun, demanded money and told them to drop their purses,” he said. “One of the students put some money on the ground and then ran.”

In an e-mail to the University community, Perrotti informed students about the robberies and urged students to be cautious and take advantage of Yale security services, including the mini-bus and the security escort service, “2-WALK.” He said police do not know if the two incidents were related.

Patten said no arrests have been made at the current time, but the cases are being investigated.

Although none of the students were seriously injured, Stiles Master Stuart Schwartz sent an e-mail to all members of Ezra Stiles College reminding them to be vigilant in response to the Lake Place incident. He said students need to exercise caution when walking in New Haven, especially at night, and remember not to prop entryway doors or leave college gates open.

“This is not the only time this has happened,” he said.

Indeed, Patten said crimes, especially robberies, committed by people riding bicycles are a growing problem in New Haven. Over the summer months, such incidents were a cause of concern throughout the city, he said.

Although crimes of this severity are not commonplace on the Yale campus, both the YPD and the New Haven Police Department have increased patrols in the areas where the attacks occurred, Perrotti said. Schwartz said that students must be extremely careful on the streets around campus, especially at night.