MANILA -- Thousands of members of Iglesia ni Cristo are holding a walkathon in Manila for the benefit of "Yolanda" survivors. Police estimated the crowd at around 500,000 from Buendia to Roxas Boulevard as of Saturday morning. Participants are also lining the streets of Pasay. The Worldwide Walk, which started early this morning and is slated to last until 6 p.m., is aimed at setting a new Guinness Book of World Records for the biggest gathering. Organizers hope to beat Singapore's current record of 70,000. Registration fees raised at the event will go to the Manalo foundation for the benefit of survivors of super typhoon "Yolanda." Over 800 personnel were deployed by the Manila Police District (MPD) to ensure the security of the walkathon participants. "Kung mapapansin niyo po, disiplinado po lahat ng dumadating dito, yung mga participants po. Kasama na po ang miyembro ng SCAN International na katulong po namin sa pagpapatupad ng kaayusan at katahimikan dito sa pagdadausan," said Sr. Supt. Gilbert Cruz, chief district directorial staff ng MPD. "Doon po sa starting point meron po tayo [mga command center]. Meron po tayong isa sa Pedro Gil at meron din po tayo dito sa finish line. Naka-deploy na yung mga pulis natin dito sa palibot ng stage at gayundin, meron din po tayong first aid stations at emergency response," he added. -- Reports from Zhander Cayabyab and Johnson Manabat, dzMM