By Ariba Shahid KARACHI, Pakistan (Reuters) -Two Chinese nationals were wounded on Tuesday by a private security guard who opened fire at a garment factory in Pakistan's commercial hub Karachi, the latest in a string of attacks that have spurred Beijing to pressure Islamabad to improve security for its citizens.

Authorities in Pakistan said Tuesday that a local security guard at a factory in the southern port city of Karachi shot and injured two Chinese nationals, the third attack this year in the country targeting workers from China.

Authorities say a Pakistani guard shot and wounded two Chinese nationals working in a textile mill in the southern port city of Karachi, but the attack was not related to militant violence.

A Pakistani guard shot and wounded two Chinese nationals working in a textile mill in the southern port city of Karachi on Tuesday, but authorities said the attack was not related to militant violence.

Sindh home minister calls for audit of security firms for compliance with standards protecting foreign nationals