Family members weep for the victims of a knife attack in which people were killed and three injured in Shenzhen, Guangdong province, July 29, 2013. [Photo/CFP]

GUANGZHOU, July 29 -- Three people died and another three were injured in a knife attack that occurred Monday in the city of Shenzhen in south China's Guangdong Province, local police said.

Police received a call at 9:45 a.m. Monday saying that a man was randomly attacking passersby with a knife on the side of a road in the city's Luohu District.

Police later detained the man and rushed the injured to the hospital, the municipal public security bureau said.

The man, surnamed He, was also sent to the hospital for treatment, as he injured himself during the attack.

The man's motive is unknown.

An investigation into the attack is under way.