Residents were baffled when they woke up to foul smells coming from the river and discovered giant foam formations on its banks.
Jolina Barrias said there was a stench in Tuy town, Batangas the Philippines so they went to check on the river on Wednesday (August 19) morning.
She said: "The smell was strong and gives us a headache when we inhaled so we went to have a look."
When the people arrived at the river, they saw the giant foam almost covering the area with its size.
The local officials sought help from the police. They later arrested two men for allegedly dumping barrels of chemicals the night before during a storm on the river.
The place where they reportedly dumped the chemicals is just a few metres away from where the bubbles formed.
Tuy Police Station chief Major Von Eric Gualberto said: "Some witnesses saw the two men washing the barrels on the river. This could have caused the bubbles to form."
Police confiscated 16 empty barrels from the two men which used to be containers of unknown chemicals.
They admitted dumping its content in the river so they could sell the barrels to a junk shop.
The men also said they bought the barrels from a closed-down factory that still had some unused materials in its warehouse.
The police said the men could be charged for violating the Toxic Substances and Hazardous and Nuclear Waste Control Act which can imprison them from six months to six years.