A student at the College of the Holy Cross in Worcester is accused of posting online threats saying he planned to “shoot up” a Massachusetts movie theater, according to authorities. Gregory Hamalian, 21, of West Bridgewater, was arrested at the school Friday night, said Timothy Connolly, a spokesman for the Worcester County district attorney’s office. Authorities were notified overnight Thursday that Hamalian had allegedly said online that “he intends to go to a Massachusetts theater and shoot it up,” Connolly said. He said the alleged threats did not specify a theater. Hamalian was held on $5,000 bail and is scheduled to be arraigned Monday in Worcester Central District Court . He faces a charge of making terroristic threats and four counts of threatening to commit a crime. He was placed on interim suspension Friday night, college spokeswoman Ellen Ryder said in an e-mail Sunday night. Hamalian is a junior and member of the track and field team at Holy Cross, she said.