Four assaults and one attempted assault that occurred on campus this weekend marked a three-day period University Police Services is calling "unusual," prompting police and Office of Residence Life officials to take extra precautions.

University police assistant supervisor William Moerschbacher said none of the incidents that occurred between early Friday and Sunday mornings appear to be related at this time, but officers have not ruled out any possibilities. He said five incidents, which occurred in a 49-hour period, was a relatively high number for a nonfootball weekend.

"It's not something that normally does occur," he said. "Especially at this severity, you don't usually have that much."

In the most serious incident, a fourth-floor Ewing Hall resident was assaulted in her dorm Saturday, Moerschbacher said.

The man entered the student's unlocked room armed with a knife or similar sharp object and threw her around, he said. Then the man, who may have been scared off, left the room after a struggle.

The victim was cut slightly in the attack, treated at Centre Community Hospital and released, police said.

Police are searching for a suspect described as 6 feet tall, weighing 200 pounds and having short blond hair and no facial hair.

In response to the assault, card-access system hours in South Halls will be extended to between 8 p.m. and 7 a.m., said Dane Foust, an assistant director for residence life.

The decision is temporary and will be re-evaluated later this week after more police investigation, he said.

Police officers, student security assistant rovers and resident assistants will make extra rounds this week to provide additional security.

Other assaults to which police said they responded:

-- A Thompson Hall resident was struck by a telephone thrown by a female acquaintance in her room early Friday morning.

-- A University Health Services employee reported a student was assaulted by an unknown man who struck him in a Sproul Hall elevator Friday afternoon. The victim's nose was broken.

-- A student reported he was assaulted by several unknown men about 4:30 a.m. Saturday morning on Shortlidge Road near South Halls. Police said the men punched the victim, knocked him to the ground and then continued to hit him. He was treated at Centre Community Hospital and released.

-- An East Halls woman reported an unknown man walked up behind her and grabbed her early Sunday morning. Police said the man displayed a weapon that may have been a knife and said, "I have a weapon. I'll hurt you." The woman yelled for help, and the man fled.

Moerschbacher said students can help prevent assaults if they walk in groups, use well-lit paths and avoid strange people. If approached, students should call University Police Services instead of confronting instigators, he said.

Students can prevent incidents like the Ewing Hall assault if they lock their doors while in their rooms late at night, he said.