Pakistan law forbids marriage below the age of 18, but some Muslim scholars say it is permissible if the bride and groom have reached puberty.
TV footage showed both children in traditional wedding clothes in the laps of policemen after the raid, the girl with tears running down her cheeks.
The parents said the wedding had been arranged to end an eight-year feud between the two families, according to a report on Express News TV.
Mazhar said he had heard about similar cases in rural areas but "it is shocking to have this right in the center of the city."
The parents would be brought before a court on Saturday, he said.
A Pakistan Human Rights Commission official, Hina Gillani, said the maximum possible punishment for the parents was one month in jail and a fine of just over $10.