Hong Kong police say they found almost 4,000 petrol bombs in two days while clearing the Polytechnic University campus.
The campus was the site of a fiery stand-off between activists and police - and on Thursday, with the protesters having left, the officers moved in.
They found 3,989 petrol bombs; 1,339 explosive items; 601 bottles of corrosive liquids; and 573 weapons.
The campus has now been handed back to the university management.
Protesters barricaded themselves inside the campus two weeks ago.
The authorities responded by sealing off the university grounds, trapping more than 1,000 protesters inside at one point.
Activists - armed with bricks, petrol bombs, and even bows and arrows - attacked the police lines during the siege.
Over the past week, most protesters either surrendered or escaped. On Friday, police said:
- 1,377 had been arrested because of the PolyU protests
- 810 were arrested when leaving the campus, with 567 nearby
- 318 people under the age of 18 had their names recorded
Hong Kong's protests started in June against a proposed law to allow extradition to mainland China, but they have transformed into a larger pro-democracy movement.