Belgian police fired water-cannon in central Brussels on Friday to drive back protesters inspired by France's "yellow vest" anti-tax movement who hurled rocks and firecrackers near the prime minister's office.
For nearly three hours, crowds of people complaining about fuel prices and a squeeze on living standards had disrupted traffic and walked the streets in an unauthorised demonstration that lacked clear leadership, largely promoted via social media.
Police said about 60 were arrested before the violence, mostly for blocking roads or carrying large fireworks.
Several hundred people wearing the fluorescent safety vests drivers must carry in their vehicles eventually converged on the office of Prime Minister Charles Michel. Some threw rocks, firecrackers and road signs towards police who doused them with high-pressure water jets.
Protests in Belgium, notably around fuel depots in the French-speaking south, have been inspired by the yellow vest -- or "gilet jaune" -- actions in France against increases in fuel duty imposed by President Emmanuel Macron's government as part of efforts to reduce emissions causing global warming.
"Michel, resign!" people chanted on Friday. Michel, a liberal ally of Macron, voiced sympathy for people's troubles on Thursday, but added: "Money doesn't fall from the sky."
His centre-right coalition faces an election in May.