Colombo hospital spokesman Dr Anil Jasinghe said Hettige has received emergency treatment for head wounds.
The attacks came after junior labour minister Mervyn Silva was held hostage by state television workers after he stormed the newsroom of Rupavahini in the company of thugs and assaulted its news director.
Before Friday's attack librarian Ranjini Aluthge was slashed by a razor while traveling on a bus, and others including journalist Lal Mawalage had been knifed.
The island's ruling Sri Lanka Freedom Party had appointed a disciplinary committee to inquire into the conduct of minister Silva.
Separately media minister Anura Yapa said he has also received a report on the incident from a one man commission of inquiry. So far no action had been taken.
Meanwhil