The Siege of PolyU was a 12 day standoff between pro-democracy protesters and the Hong Kong Police at the Hong Kong Polytechnic University. Protesters occupied the campus and blocked nearby highways as they battled with police, turning the campus into a war zone. Police eventually surrounded the campus for over a week, forcing protesters to flee or surrender themselves. Police used over 1,500 rounds of tear gas, 1,300 rubber bullet rounds and 300 bean bag rounds on the first day of the siege. The next day hospitals overflowed with the thousands of injured protesters from the battle.