In this photo provided by the Cagayan Police Provincial Office, a town is surrounded by floodwaters after the onslaught of Typhoon Fung-wong in Cagayan province, northern Philippines on Nov 11. (AP)

MANILA, Philippines, Nov 16, (AP): Tens of thousands gathered Sunday for the start of a three-day rally organized by a religious group in the Philippine capital to demand accountability over a flood-control corruption scandal that has implicated powerful members of Congress and top government officials. It’s the latest show of outrage over accusations of widespread corruption in flood-control projects in one of the world’s most typhoon-prone countries.

Various groups have protested in recent months following the discovery that thousands of flood defense projects across the country were substandard, incomplete or simply did not exist. Government engineers, public works officials and construction company executives have testified under oath in hearings by the Senate and a fact-finding commission that members of Congress and officials at the Department of Public Works and Highways took kickbacks from construction companies to help them win lucrative contracts and avoid accountability.

Most denied the allegations. Police estimated about 130,000 members of the Iglesia Ni Cristo gathered in Manila’s Rizal Park by mid-afternoon ahead of the rally, many wearing white and carrying anti-corruption placards. Other groups were scheduled to hold a separate anti-corruption protest later Sunday at the "People Power” monument in suburban Quezon city. Iglesia is an influential group that votes as a bloc and is courted by political candidates during elections.

The police, backed by the military, went on full alert and deployed thousands of personnel to secure the weekend rallies, although the government expects them to be peaceful, according to a confidential security assessment seen by The Associated Press. During a Sept. 21 anti-corruption demonstration, a few hundred black-clad protesters threw rocks, bottles and firebombs at policemen near the presidential palace in Manila, injuring more than 100 officers.

Criminal complaints have been filed against 97 protesters. The presidential palace went on security lockdown over the weekend, with major access roads barricaded by anti-riot police forces, cargo containers and barbed wires. National police chief Lt Gen Jose Melencio Nartatez Jr. ordered law enforcement to exercise "maximum tolerance” in Sunday’s rallies.

Flood control is an especially sensitive issue in the Philippines, one of Asian countries most prone to deadly typhoons, flooding and extreme weather. Two typhoons left at least 259 dead this month, mostly from flash floods and landslides, as millions of others were forced to evacuate.