At least 10,000 pro-democracy protesters marched on Thailand’s police headquarters on Wednesday, spraying it with paint and water pistols, a day after violent clashes in which six people were shot and dozens more injured. Protest leaders condemned the police for using chemical-laced water cannon and teargas against them, chanting “slaves of tyranny” and “our taxes”, and pelting paint at their compound. Some sprayed toy water guns to protest against the police response. A rally on Tuesday, held outside parliament as legislators considered proposals to reform the constitution, was marked by the highest number of injuries of any demonstration since the youth-led protest movement emerged in July. Several MPs fled from the riverside parliament on boats as royalists clashed with demonstrators. Later in the night, gunshots were fired. Despite the violence, at least 10,000 people packed into the Ratchaprasong intersection in Bangkok on Wednesday, where protesters vowed to step up their movement. As crowds gathered outside the police headquarters, a speaker chanted: “Down with feudalism, down with dictatorship.” “We don’t have weapons, we don’t have the army,” said Thanisorn, a 22-year-old protester, who held a children’s water pistol. But she added: “I felt I have to come out to tell them I’m not afraid of them. We are stronger than them.” “The people have already woken up. It’s not the propaganda age any more,” she said, adding that people want change. The pro-democracy protest movement is one of the biggest challenges facing the Thai establishment in living memory. Protest leaders have shocked the country by demanding reforms to the monarchy, an institution long considered beyond direct, public criticism. They believe its powers should be curbed, and that it should no longer be protected by harsh defamation laws. They are also calling for the removal of the prime minister, Prayuth Chan-ocha, a former army general who first took power in a 2014 coup, and for reforms to the constitution, which was passed under military rule. Since Tuesday, legislators have been considering several proposals to change the charter, but a draft favoured by the protesters was rejected, despite receiving support from about 100,000 members of the public. The draft, unlike other proposals, did not rule out changes relating to the monarchy. It also stated that the 250 military-appointed senators should be replaced with elected officials. Two motions to set up a constitution drafting committee did pass, but they will have to go through second and third votes after at least a month. “The country is not democratic as the government likes to say,” said Oat, 27, who joined Wednesday’s protest after work. “I want a government that listens to the people’s wants and demands.” If the king cared about calls for reform, he added, “he would have reduced his power through the parliament”. Protest leaders plan to intensify pressure on the authorities by holding seven days of rallies, starting with a major demonstration outside the Crown Property Bureau on Wednesday. In 2017, King Maha Vajiralongkorn took direct control of the CPB, which is thought to be worth £30bn. Many attending Wednesday’s protest wore helmets, goggles and hard hats for protection, though the evening passed without violence. Giant inflatable ducks – which were used on Tuesday by protesters to shield them from water cannon and have since been adopted as a protest symbol – were passed along the crowds. “We should not be afraid – this is just a transitional moment in our history,” Sirapop Poompuengpoot, a student leader, told the crowds. A police spokesman said water cannon were used on Tuesday because protesters were attempting to break into a restricted area near to parliament. Police have also said they had not fired either live rounds or rubber bullets, and that they were investigating who was behind the shootings of six people. The Thai Human Rights Lawyers Association has condemned the police tactics, saying they were “not in accordance with international procedure to disperse demonstrations”. Kan, 21, who came to Wednesday’s rally with a friend, said the police crackdown made her even more determined to turn out. “I am worried but right now what we demand, what we said we would fight for, is not achieved. We have to fight.”