SATV Kathmandu Sept 22: Thousands of Filipinos have marched in the capital to vent their anger over a ballooning scandal involving bogus flood-control projects believed to have cost taxpayers billions of dollars.

The protest on Sunday was largely peaceful but erupted into violence as riot police deployed water cannon in clashes with scores of mostly young masked people who hurled rocks and shattered the glass of one police outpost.

Police arrested 72 people — including 20 minors — in two separate incidents that saw at least 39 officers injured and a trailer that was being used as a barricade set ablaze, according to a spokeswoman.

Major Hazel Asilo said it was unclear if those arrested were "protesters or just people who are causing trouble".

Rage over the so-called ghost infrastructure projects has been mounting in the South-East Asian country since President Ferdinand Marcos put them centrestage in a July state of the nation address that followed weeks of deadly flooding.

Mr Marcos said early last week he did not blame people for protesting "one bit".

Sunday in the capital began without violence with a morning demonstration at a park that drew nearly 50,000 people, according to city estimates.

'This is enough'

"It's very rare for me to go to rallies, but this situation was bad enough that I was really urged to say 'this is enough,'" Mitzi Bajet, a 30-year-old designer, said.

Teddy Casino, 56, chairman of left-wing alliance Bagong Alyansang Makabayan, said his group was demanding not only the return of stolen funds, but also prison time for those involved.

"Corruption requires people to go to the streets and express their outrage in the hope of pressuring government to actually do their jobs," he said.

Renato Reyes, another organiser of the first protest, later said he had been hit in the face with a rock as he tried to leave an area near the presidential palace.

"They could be provocateurs or they could just be really angry at what is happening," he said of the masked protesters, adding the government could not "ignore the problem of corruption".

Some of those at the clashes could be seen holding aloft the pirate flag seen at recent Indonesian protests — sparked by low wages, unemployment and anger over lavish politicians' perks — that left at least 10 dead.

According to the AFP news agency, a journalist at the scene witnessed police throwing rocks back towards protesters, something Major Asilo.

Billions lost

The Department of Finance has estimated the Philippine economy lost up to 118.5 billion pesos ($3 billion) from 2023 to 2025 due to corruption in flood control projects.

Greenpeace has suggested the number is actually closer to $27 billion.

Earlier this month, the owners of a construction firm accused nearly 30 House of Representatives members and Department of Public Works and Highways officials of taking cash payments.

The scandal has already sparked leadership changes in both houses of Congress, with House speaker Martin Romualdez, a cousin of Marcos, tendering his resignation earlier this week as an investigation got underway.

On Sunday, multiple politicians were among those taking part in the protest, an event supported by the powerful Catholic Church that drew numerous families.

"This is not partisan," said 58-year-old Manuel Dela Cerna.

"They are draining the people's money while citizens suffer from floods, their homes being swept away, while officials ride private planes, live in mansions," he said.

The Philippines has a long history of scandals involving public funds, in which high-ranking politicians found guilty of corruption have typically escaped serious jail time.