But as police escorted Silva to his car, members of the surrounding crowd pelted him with stones and sprayed him with paint and urine, according to witnesses.
Silva, one of the government's 36 non-cabinet ministers, has himself repeatedly been accused of threatening reporters.
Held captive
The incident occurred after Silva entered the channel's premises on Thursday, according to news reports, and complained that a speech he made the previous day to reopen a bridge destroyed by the 2004 tsunami had not been broadcast.
His aide then allegedly dragged the news director out of the newsroom, tearing open his shirt.
The broadcaster's irate staff hemmed the minister and his entourage into a small room, and would not let them leave, demanding an apology.
"The minister is being held in an office by the staff," the television announced in a statement, interrupting its regular programming.
Staff then released the minister after he issued a public apology.
Unedited footage broadcast live over the state television channel showed army officers and police escorting Silva out of the building.
"Unfortunate" incident
Afterwards, Silva was admitted to Colombo hospital with a head injury, which was not critical, said Dr Hector Weerasinghe, the hospital director.
"He has some head injuries and we have put stitches. For further observation and treatment we have admitted him to the hospital," he said.
Police arrested one person on suspicion of assaulting Chandrasekara, the TV channel's news director, an unnamed senior police officer said.
Silva's past rows with the media have led the incident to raise questions about government corruption and the behaviour of senior officials towards the media.
"This is not the first time minister Silva did this. The government should take strict measures against him," Sunanda Deshapriya, an official with the Free Media Movement, a local media rights group, said.
Anura Priyadharshana Yapa, Sri Lanka's media minister, called the incident "unfortunate".