MANILA (Philippines) - THOUSANDS of Filipinos in a Manila suburb honoured their patron saint John the Baptist by drenching passers-by and motorists in a raucous annual water festival Wednesday.

Police intensified street patrols to prevent any scuffles in San Juan, where armies of residents - some armed with drums of rainwater from a tropical storm - woke early to train water guns, high pressure hoses and buckets on shrieking crowds.

One small child dumped a bucket of water on a police officer; he managed to keep his cool along with most of the commuters caught up in the one-day celebration in the heart of the Philippine capital.

Mayor JV Ejercito joined the annual merrymaking by riding in a convoy of fire trucks that used their water cannons to drench children and other revellers under an overcast sky.

The ritual to commemorate Christ's baptism by John the Baptist has been celebrated for decades in the Philippines, Asia's largest predominantly Roman Catholic nation.

Susan Samuele, a 40-year-old mother of four, filled six water containers with rain water dumped by an approaching storm overnight then waited with her cousins and friends in a congested alley armed with toy water guns. By noon, she said she has ambushed about 100 passers-by, and not one had complained.

'It's clean fun with clean water,' Samuele said.

A tropical storm is expected to blow past Manila late Wednesday, forecasters said.

Reveller Nio Suedad said he chilled a drum of water with blocks of ice 'to add thrill to the fun.' While the frenzy draws large numbers of tourists each year, many avoid San Juan to stay dry. The ritual has sparked scuffles in past years when some residents threw dirty canal water on passers-by. -- AP