Thousands of people flooded the streets of Argentina's capital for hours Thursday night and many others marched in cities worldwide in the country's biggest anti-government protest in more than a decade.

Angered by high inflation, violent crime and high-profile corruption, and fearful President Cristina Fernandez will try to hold onto power indefinitely by ending constitutional term limits, protesters marched on the iconic obelisk in Buenos Aires chanting: "We're not afraid."

In a march organized on social media, demonstrators also converged on the pink presidential palace at the Plaza de Mayo square in scorching heat. There was little rowdiness, and the protest had the air of a family affair, with toddlers in strollers and grandparents in wheelchairs joining in.

People banged on pots, whistled and waved the Argentine flag. They held banners that read: "Stop the wave of Argentines killed by crime, enough with corruption and say no to the constitutional reform."

"I came to protest everything that I don't like about this government and I don't like a single thing starting with (the president's) arrogance," said Marta Morosini, a 74-year-old retiree.

"They're killing policemen like dogs, and the president doesn't even open her mouth. This government is just a bunch of hooligans and corrupters."

Police officials said the crowd numbered at least 30,000, while some local media put it at hundreds of thousands. People started heading home a little before midnight, although the Plaza de Mayo remained crowded.