Brown University shooting: Police release new footage as search for gunman continues

US police have released new footage of a man they are searching for after a gunman killed two students and wounded nine others at Brown University.

The gunman opened fire inside a classroom in the engineering building on Saturday afternoon, shooting more than 40 rounds from a 9mm handgun, a police official said. The shooting took place as final exams were under way and sparked hours of chaos on the campus and in the surrounding neighbourhoods, leading to a frantic police search, with hundreds of officers involved.

The following day, a "person of interest" was released from custody when police said the evidence pointed "in a different direction". The release was announced by authorities at a news conference late on Sunday, marking a setback in the investigation into the university attack in Providence, Rhode Island.

CCTV released by Providence Police today shows a man walking on the pavement in a road with cars driving past at 4.06pm. He appears to be dressed all in black, but his face is not visible.

Read more from Sky News:Four charged with New Year's Eve plot to bomb multiple targets in CaliforniaDonald Trump launches attack on Rob Reiner after film director found stabbed to death "Right now, we don't have any evidence to suggest that it was more than that individual," Providence mayor Brett Smiley said after the release of the footage. Two handguns were recovered when the original person of interest was taken into custody and police also found two loaded 30-round magazines, a police official said.

Investigators were not immediately sure how the gunman got inside the first-floor classroom, housed in a seven-storey complex. Police had announced early on Sunday that they had detained a person of interest at a Rhode Island hotel in connection with the attack and lifted a lockdown at the Ivy League school's campus.

One video of the attack showed students in a library shaking and wincing as they heard loud bangs just before police entered the room to clear the building. During the lockdown, which was not lifted until Sunday, many students remained barricaded in rooms, while others hid behind furniture and bookshelves as police searched for the gunman.

One of the nine wounded students has been released from the hospital, university president Christina Paxson said on Sunday. Seven others were in critical but stable conditions, and one was in a critical condition.

Brown, the seventh-oldest higher education institution in the US, is one of the nation's most prestigious colleges, with around 7,300 undergraduates and more than 3,000 graduate students. The school cancelled all remaining classes and exams for the semester..