Police in Kerala have registered 19 cases in connection with an online campaign discouraging donations for flood relief, sources confirming that an investigation has begun with help from the cyber cell to trace those behind such negative messages.

Chief minister Pinarayi Vijayan had warned on Sunday that people who have been posting such messages could be brought to justice.

Torrential rain and multiple landslides since Thursday have left 89 people dead in the state while more than 50 have been reported missing. Around 2.5 lakh people have been accommodated at over 1,500 relief camps.

The state government has been battling the floods, Kerala’s second with a year, but the campaign — essentially allegations that last year’s donations to the Chief Minister’s Disaster Relief Fund (CMDRF) had been misused for Vijayan’s travel abroad — has left a jarring note.

A police source said several social media accounts were being monitored for such false messages.

Vijayan on Tuesday toured several relief camps in Wayanad, one of the districts worst hit in the north. “We can face this challenge together. Among those in the relief camps are people who have lost their homes. Some lost their near ones. We will overcome this together,” the CPM leader told inmates of a relief camp in Meppadi as rainfall intensified in the southern districts.

Ernakulam, Idukki and Alappuzha have been put on red alert as the rain shifted trajectory. Kochi, in Ernakulam, was partly flooded while the water level in the Kuttanad backwaters in Alappuzha breached the banks, swamping several villages in a repeat of last year’s floods that killed 480 people. The government has asked police to stop all tourists headed for Idukki amid fears of possible landslides.