BUCHAREST, Romania — Antigovernment protests in the Romanian capital turned violent Friday night as the police clashed with protesters, using tear gas and water cannons to disperse the crowds. More than 240 people, including some security personnel, were reported injured.

An estimated 100,000 people gathered throughout the day in Bucharest’s Piata Victoriei to express their anger at the government, with tens of thousands protesting in other cities across the country. Chief among their grievances are legislative changes that many say will weaken the rule of law.

“We want democracy and laws that defend citizens, not politicians,” said Moise Maracine, 33, who flew from Britain, where he lives and owns a business.

Organizers sought to draw Romanians living outside the country to this demonstration, the latest in a series.