“The scenes today at the Bronte Hotel have no place in our society and we are urgently investigating the matter to understand exactly what happened,” he tweeted.
“Over the past nine months we have protected freedom of speech, of assembly and the right to criticise the government.
“This is an indispensable part of the new Zimbabwe. It is non-negotiable and will not change.
“We won the election freely and fairly, and have nothing to hide or fear. Anyone is free to address the media at any time,” he said.
Heads are likely to roll within the police force as there were already moves to get rid of those said to have been loyal to former police chief Augustine Chihuri.
Mnangagwa, however, did not want to rock the boat too much before obtaining his own mandate.