The police said the protesters pelted them with stones and smashed windscreens of more than a dozen buses and cars near Indian Oil Chowk here.

The employees, on a hunger strike for the past 108 days, however blamed the Noida Authority and the police for “conniving”. The Authority officials on their part said they are “innocent”.

About 50 temporary employees had attacked the office of Chetram, who had registered a complaint against 31 employees fearing disruption of basic civic facilities. Officials said the complaint was registered after employees declared a “tools down” protest on Tuesday, raising fears that water supply in the area could be affected. “Most employees in the water department are on contract and we feared they could cripple supply lines today,” an official said.

Following the complaint, the Noida Police arrested all 31 employees outside the Authority office on Tuesday night — at about 1 am. “The arrests were made under Section 151 of IPC as a preventive measure,” Paresh Pandey, SP (City), said.

Meanwhile, political parties at the district level have come out in support of the protesting employees. Criticising the arrests, Jaiveer Kasana, a leader of Janmorcha Party in Noida, said, “It is a conspiracy to deprive the poor of their deserved right.” The employees have been demanding regularisation and an increase in wages. They have been sitting on a relay hunger strike outside the Authority office for close to 16 weeks now.

“No violence occurred during our protests — we held a Gandhian protest. Why then should we be targetted in a way that is nothing but the exploitation of the voiceless?” Kasana said.

Employees have claimed the police didn’t even spare women during their lathicharge. “Many people, among them six women who were already weakened by the hunger strike, were beaten up and have since been hospitalised,” a representative of the Safai Mazdoor organisation said.

While the Noida police are claiming innocence and Authority officials say they are more concerned about basic facilities, the protesting employees said they would carry on the fight and will gherao the Authority office on Thursday. A meet was organised in Sector 2 after the incident and a decision was taken among the employees to continue the “tools down” protest.