MANILA, Philippines — Thousands of demonstrators including from the Roman Catholic church clergy protested in the Philippines on Sunday, calling for the swift prosecution of top legislators and officials implicated in a corruption scandal that has buffeted the Asian democracy.

Left-wing groups led a separate protest in Manila’s main park with a blunt demand for all implicated government officials to immediately resign and face prosecution.

President Ferdinand Marcos Jr. has been scrambling to quell public outrage over the massive corruption blamed for substandard, defective or non-existent flood control projects across an archipelago long prone to deadly flooding and extreme weather in tropical Asia.

More than 17,000 police officers were deployed in metropolitan Manila to secure the separate protests. The Malacanang presidential palace complex in Manila was in a security lockdown with key access roads and bridges blocked by anti-riot police forces, trucks and barbed wire railings.

In a deeply divided democracy where two presidents have been separately overthrown in the last 39 years partly over allegations of plunder, there have been isolated calls for the military to withdraw support from the Marcos administration.

The Armed Forces of the Philippines has steadfastly rejected such calls and welcomed on Sunday a statement signed by at least 88 mostly retired generals, including three military chiefs of staff, who said they “strongly condemn and reject any call for the Armed Forces of the Philippines to engage in unconstitutional acts or military adventurism.”

“The unified voice of our retired and active leaders reaffirms that the Armed Forces of the Philippines remains a pillar of stability and a steadfast guardian of democracy,” the military said in a statement.

Roman Catholic churches across the country helped lead Sunday’s anti-corruption protests in their districts, with the main daylong rally being held at a pro-democracy “people power” monument along EDSA highway in the capital region. Police said about 5,000 demonstrators mostly wearing white joined before noon.

They demanded that members of Congress, officials and construction company owners behind thousands of anomalous flood control projects in recent years be imprisoned and ordered to return the government funds they stole. A protester wore a shirt with a blunt message: “No mercy for the greedy.”

Since Marcos first raised alarm over the flood control anomalies in his state of the nation address before Congress in July, at least seven public works officers have been jailed for illegal use of public funds and other graft charges in one flood control project anomaly alone. Executives of Sunwest Corp., a construction firm involved in the project, were being sought.

On Friday, Henry Alcantara, a former government engineer who has acknowledged under oath in Senate inquiry hearings his involvement in the anomalies, returned 110 million pesos ($1.9 million) in kickbacks that justice officials said he stole and promised to return more in a few weeks.

About 12 billion pesos ($206 million) worth of assets of suspects in flood control anomalies have been frozen by authorities, Marcos said.

Marcos has pledged that many of at least 37 powerful senators, members of Congress and wealthy construction executives implicated in the corruption scandal would be in jail by Christmas.

Protesters in Sunday’s rallies said many more officials, including implicated senators and House of Representatives members, should be jailed sooner and ordered to return the funds they stole and used to finance fleets of private jets and luxury cars, mansions and extravagant lifestyles.