Police have warned students at Harvard’s Longwood medical campus not to walk alone at night after two women were raped at gunpoint in Boston over the last two weeks, one of them in Longwood’s Mission Hill neighborhood.

After the Boston Police Department (BPD) alerted media and local universities Thursday about the two rapes, the Harvard University Police Department (HUPD) sent an advisory to the Longwood campus the same day.

But some students at the College asked why they had not received direct notification from HUPD about the violent attacks.

A 19-year-old woman was assaulted just before midnight last Wednesday on Hillside Avenue in Mission Hill, according to the BPD. In a similar incident, a 23-year-old woman was attacked near the Forest Hills Orange Line station in Jamaica Plain around 9:45 p.m. on Sept. 21.

In both cases, the victim was pulled into a car and taken away to a location where the two male abductors pistol-whipped and threatened to kill the victim before raping her.

While news of the attacks reached several student group and House e-mail lists, members of the Coalition Against Sexual Violence (CASV) said they should have received an alert from HUPD.

Tazneen R. Shahabuddin ’06, a CASV board member, said CASV found out about the incidents after a member posted an article from the Boston Globe to their e-mail list.

“I would always err on the side of caution,” she said. “Maybe they were trying not to stir up panic...but it’s always nice to have the information.”

Harvard police make a “case by case” decision about how widely to distribute crime alerts, said HUPD spokesman Steven G. Catalano.

“In this case...with Boston police intelligence that these individuals were acting in that area, we felt that it was appropriate to send that advisory just to the Longwood campus,” he said.

Another CASV board member, Laura E. Openshaw ’05, said she was especially concerned because the suspects in both incidents used cars in the abductions, which means that the threat they posed might not be limited to the Boston neighborhoods where the crimes took place.

The Longwood area, which includes Harvard Medical School and the Harvard School of Public Health, is about 15 minutes by car from Cambridge.

Susan B. Marine, the director of Harvard’s Office of Sexual Assault Prevention and Response, said she supported HUPD’s decision to send the advisory only to the areas where the incidents occurred.

“There are rapes and other kinds of sexual assaults reported every single day in the Boston area, including in Cambridge,” she wrote in an e-mail. “I am sorry to say that I think if we sent an alert every time a rape was reported, people would simply stop paying attention to them.”

Some 30 or 40 students from Harvard and other area colleges travel to the Longwood neighborhood each day Monday through Thursday to volunteer at the Mission Hill After-School Program, according to Natalia Mendoza ’05, the program’s administrative director.