Hong Kong police have conducted raids ahead of Sunday afternoon's protest rally, uncovering several weapons, including a pistol with more than 100 bullets.
Eleven people were arrested during the raids.
Daggers, swords, batons and pepper spray were also recovered in the raids at several locations.
The city's organized crime bureau said it believed protesters planned to use the weapons during the demonstration "to incite chaos" and "impugn the police."
The territory is bracing for a large turnout for Sunday's protest. Hong Kong has given its approval for the rally called by the Civil Human Rights Front, a group that has organized some of the city's biggest demonstrations.
Monday marks the sixth month anniversary of the rallies that were initially mounted to rally against a now-withdrawn government proposal that would have allowed Hong Kong criminal suspects to be spent to mainland China's Communist-controlled courts to stand trial.
The demonstrations have transformed into a push for democratic elections for the city's leader and legislature and an investigation into what protesters say has been excessive force used against them.