Kano, the largest city in the mainly Muslim north, has been attacked repeatedly by Boko Haram Islamists but it was not clear if the insurgent group was behind the latest violence.
"I can confirm the kidnap of a Lebanese national by unknown gunmen from his factory in Sharada area this morning," Kano state police spokesman Magaji Majia told AFP.
"It is too early to say who was behind the abduction but investigations have commenced," he added.
The employees said five assailants stormed the factory compound at around 8:00 am (0700 GMT).
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"As soon as (the Lebanese owner) stepped out of his car the gunmen stormed into the parking lot firing in the air which caused a stampede," said a worker who gave his first name as Musa.
"Workers rushed inside for safety," he added, but said the attackers also fired directly on the security guard, leaving him with serious injuries.
A female employee was also shot and wounded, said Musa, in an account confirmed by other witnesses.
Kano, like many west African cities, is home to large Lebanese population.