A surreal, blood-red river has inundated the Indonesian village of Jenggot in the wake of floods hitting a nearby textiles factory, causing a frenzy on social media.

Thousands of Twitter users have shared photos and videos of the village south of Pekalongan in Central Java being flooded by crimson-coloured water, with some saying it reminded them of blood.

Pekalongan is a city known for batik, a traditional Indonesian method of using wax to resist water-based dyes to depict patterns and drawings, usually on fabric.

“I am so afraid if this photo gets into the bad hands of hoax spreaders,” Twitter user Ayah E Arek-Arek said.

“Fear mongering narratives about signs that it is the end of the world, bloody rain etc.”

It is not uncommon for rivers in Pekalongan to turn different colours.

Bright green water covered another village north of the city during a flood last month.

“Sometimes there are purple puddles on the road too,” Twitter user Area Julid, who claimed to be from the area, said.

A 2018 study found that wastewater from the batik industry was having a negative impact on the environmental health of residents in Pekalongan, and recommended the installation of wastewater treatment facilities.

The section head for disaster mitigation and preparedness of the Pekalongan Disaster Mitigation Agency, Dimas Arga Yudha, confirmed that the photos being circulated were real.

“The red flood is due to the batik dye, which has been hit by the flood. It will disappear when it mixes with rain after a while,” he said.

Police told local media they were looking for those responsible for discarding the used dye that discoloured the floodwaters.

The Pekalongan Environmental Service said it had used a truck to suck up the floodwaters.

-ABC/Reuters