Some 150 migrant workers were detained in Ernakulam district on Sunday after they allegedly broke out in a drinks and drugs-fuelled riot and later attacked policemen and their vehicles.

The workers, from northern and eastern states, first clashed among themselves around midnight after a Christmas party turned violent at the Kitex Garments workers’ camp in Kizhakkambalam, the police said.

Informed by local people, the police arrived in the early hours. But the rioting workers allegedly assaulted them with sticks and stones, leaving several policemen injured.

Video clips show a mob smashing police vehicles. Some of the workers allegedly tried to lock the doors of a patrol car before setting fire to it, but the policemen inside managed to escape. The patrol car was destroyed.

The rioting continued for several hours with many of the workers throwing stones from inside their camps, the police said. A large contingent of riot police later controlled the situation. After six hours, 151 migrant workers were taken into custody.

The migrants are among the 3,000 employees of Kitex Garments, one of the largest exporters from the state, and live in workers’ camps near the facility.

“Two police vans have been completely damaged (one of them burnt), 151 workers have been taken into custody and 10 policemen have been injured in the incident,” labour minister V. Sivankutty told reporters.

“Preliminary reports suggest the incident happened during Christmas celebrations.”

Sabu M. Jacob, managing director of Kitex Garments, accepted that the workers were under the influence of drugs but said they may have consumed the drugs unwittingly.

“I feel someone delivered the drugs to them. Perhaps they consumed it inadvertently. They did this (rioting) under the influence of drugs,” he said.

“I doubt they would even remember what they did if you ask them now. It’s an unexpected incident and not a planned criminal attack.”

Ernakulam rural superintendent of police K. Karthick, who led the operation to contain the situation, told reporters the workers were drunk.

Congress and CPM leaders said many of the migrant workers were troublemakers and asserted that the Kitex management could not evade responsibility for the rioting by its employees.

P.V. Srinijin, local MLA from the CPM, said: “I have been receiving a lot of complaints (from local people) about the workers’ behaviour and have always forwarded them to the officials concerned. The labour department had visited the place to conduct an inquiry based on my complaints.”

He added: “But the company management unleashed a major propaganda that Kerala is not an investment-friendly state. No action followed after that campaign.”

Lok Sabha member Benny Behanan of the Congress described the rioters as “goons” nurtured by Twenty20, a Kitex-sponsored political party that runs the Kizhakkambalam panchayat.

“Twenty20 is playing this game and this place has for long been a den of goons. Those living here (in the camps) are nurtured by Twenty20 to unleash attacks on people like us,” said Behanan.

Kitex Garments and its sister concern, Anna Aluminium, started Twenty20 as an NGO in 2013 and converted it into a political party two years later. It then won the local panchayat election, sweeping 17 of the 19 seats. In December last year, Twenty20 retained Kizhakkambalam and won three neighbouring panchayats.