Sand sprinkled on Mir Bahar Ghat Street after the slippery paste was washed away. (Bishwarup Dutta)

A mysterious white powder found scattered on a Burrabazar road on Sunday morning got mixed with Holi water and turned a 75-metre stretch into a fun-slide zone for kids and skid-scare zone for adults.

At least three bikers fell after skidding on the slippery paste on Mir Bahar Ghat Street, off Strand Road, in 15 minutes when the residents realised it wasn’t all fun.

The fire brigade had to be called in around 9.45am. Two fire tenders sprayed water for over an hour to clean the road but the cordon remained till 12.30pm.

Half a dozen firefighters struggled to complete their work while keeping themselves on their feet.

It took over 13,000 litres of water and three hours to clean the road.

“The powder got slippery as soon as it came in contact with water. We had to wash away every bit of the solution to make the road safe. But the greatest challenge was to keep standing on the slippery surface,” said a firefighter.

After the firemen left, a police team arrived and sprinkled sand on the road rendered muddy by the long spray of water.

No heavy vehicle was allowed on the stretch till around 3.30pm when the police finally declared it safe.

The police collected samples of the slimy substance from the road to get them tested by forensic experts.

Neither the police nor the firemen had any clue about what the white powder, first spotted by the locality’s children around 9am, could be. As they started playing with colours on the road, the water and the powder got mixed and resulted in a colourful slimy mass.

“We had earlier ignored the white powder. But as soon as it came in contact with water, it turned into a slippery paste. Our kids were sprinkling watercolours on each other. In no time, they started skidding in the white paste,” said homemaker Gauri Majumdar. “We tried to sweep the area clean. But that only resulted in expanding the affected area,” said another woman.

Seven-year-old Bunty Sen said Holi had never been this fun for him. “It was like park in the middle of the road. We were competing among friends to skid along the road without falling,” he said.

Luckily, no one was injured seriously. “But the consequences could have been different for four-wheelers. They could have lost control and hit the children playing Holi. So that stretch had to be cordoned off,” said an officer of the Burrabazar police station posted at a kiosk barely a few meters from the spot.

A fireman said they were not qualified to comment on the nature of the slimy paste.

A local police officer said the white powder could be a “dry adhesive” that local furniture makers.

Forensic sources said it was more likely to be dry soda or a detergent.

A biochemist attached with a state forensic laboratory said: “If the substance was just slippery without any lather, chances are, it was soda. If it was slippery producing lots of foam when mixed water, more likely it was some detergent powder. And if the substance was more sticky than being slippery it might be some dry adhesive.”

Rajakatra residents said it was more slippery than sticky or foamy. “The children were having fun on it but we got alarmed when the bikers started falling,” said a Moumita Sen, whose son was among those on the road.

The police said they did not know how the suspected dry adhesive landed on the road on a day when all the furniture shops were shut. “Maybe it fell during an unloading operation early in the morning. There are many shops in Rajakatra that need such adhesive. But since all the shops are closed today, we have not been able to make a proper inquiry,” said an officer.

The forensic scientist said: “There are even instances when adhesive materials lose their sticky nature and turn very lucid if they are mixed with excess water. The true nature of the white powder can be ascertained only after chemical analysis.”