An official at Hong Kong's Polytechnic University said on Wednesday they had not found any protesters left on campus, signalling the end of a siege that saw anti-government demonstrators barricade themselves on the college grounds.

"We have tried our best to handle this matter. We have already done what we could do. We hope we can re-open the school soon to start our renovation work and reduce the impact on our students and our research projects," said Polytechnic University Executive Vice President Dr Miranda Lou.