A gunman opened fire at a university in the US state of Virginia on Monday, killing 32 people, and then committing suicide.
The shooting started in a Virginia Tech dormitory and then started again in a classroom building across campus two hours later, killing 32 people in the deadliest shooting rampage in U.S. history.
The gunman committed suicide, bringing the death toll to 33.
Students said there were no public-address announcements or other warnings on campus until an e-mail more than two hours after the first shooting of two people. By then, the gunman had struck again, killing 31 others, including himself.
Later on Monday students began leaving the campus, packing up cars as they were picked up by relatives and friends.
Virginia Tech President Charles Steger said authorities at first believed that the shooting at the dormitory was a domestic dispute and mistakenly thought the gunman had fled the campus.
Investigators offered no motive for the attack. The gunman's name was not immediately released, and it was not known if he was a student. At least 26 people were injured.
Earlier in the day, the police chief said he believed there was only one gunman, but at an evening news conference, he and the university president said they were still investigating whether the shootings were definitely related, or carried out by different people.
The shootings spread panic and confusion on campus, with witnesses reporting students jumping out classroom windows to escape the gunfire.
Later, students could be seen packing their bags and leaving, some accompanied by relatives.
Flags at the campus flew at half mast, and there was a heavy police presence.
Monday's bloodbath took place at opposite sides of the 2,600-acre (1,050-hectare) campus, beginning at about 7:15 a.m. (1115 GMT) at West Ambler Johnston, a co-educational hall of residence that houses 895 people, and continuing about two hours later at Norris Hall, an engineering building.
At least 26 people were being treated at three area hospitals for gunshot wounds and other injuries, authorities said. Their exact conditions were not disclosed, but at least one was sent to a trauma centre and six were in surgery, authorities said.