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.