Around 1,000 employees of a factory in Noida manufacturing phones for Chinese companies protested outside the plant on Thursday after around 200 of them were asked to go on leave, reported PTI. The protestors hurled stones at the building and barged into the facility.

An unidentified police officer said the plant’s management had asked the workers “to go on leave for 15 days” and denied them access to the plant, reported the Hindustan Times. The manufacturing unit in Block A of Sector 63 belongs to Hipad Technology India Private Limited, which makes Oppo and Xiaomi phones.

“In this business, we all know that going on leave means getting fired and that is why workers got angry,” said Arjun, an employee. “They were being laid off without any prior information and that is not fair. The management told our bosses that they would employ us in a second plant nearby but that would take some time. What do they expect us to do in the meantime?”

A unidentified official at the company said their contract mentions that services of contractual staff can be “terminated at any point of their tenure without any prior notice”.

The police were deployed at the plant after the protests turned violent, reported The Hindu. Superintendent of Police (Noida City) Sudha Singh said the company has not lodged a formal complaint. An unidentified police officer said at least four people have been detained for questioning.

Assistant Labour Commissioner Harish Chandra Singh said the protests occurred because of miscommunication. The management had asked three contractors to reduce staff due to a shortage of raw material, he added. “However, the vendors didn’t do so,” Singh said on Thursday. “Today, they put up a list of 200 employees, asking them to go on leave, which the workers mistook as firing.” Singh said the plant will remain closed till Monday.