KARACHI – A Pakistani security guard shot and wounded two Chinese nationals working in a textile factory in the southern port city of Karachi, but authorities said the attack was unrelated to militant violence.

China has often called for better security for its citizens working in Pakistan. Last month, two Chinese were killed in a suicide car bomb attack outside Karachi airport.

Thousands of Chinese are in Pakistan to work for Beijing’s multibillion dollar Belt and Road Initiativewhich builds major infrastructure projects. An unknown number of Chinese also work in the country’s factories.

Suhail Jokhoio, a spokesman for the province’s interior department, said the guard involved in the attack on the textile factory had been arrested and that police were still investigating to determine why he opened fire.

He said the injured Chinese were taken to hospital.

Pakistan has said it is committed to providing full security to Chinese workers.

“Pakistan remains determined to bring the person responsible to justice,” the Foreign Ministry said, adding that it was in close contact with the Chinese Embassy in Islamabad.