Two people were slightly injured in an explosion that occurred in north China's municipality of Tianjin on Friday, authorities said Saturday.

The blast occurred near the municipal government building in the city's Hexi District. A man surnamed Liu, who is suspected of setting off the explosion, has been detained, according to a government spokesman.

Liu, a local resident, is believed to have set off the explosion as a form of "revenge against society," according to the spokesman.

A police investigation is under way.