Rallies swept the streets around the parliament building, which was surrounded by tens of thousands of people angry at authorities who said the companies had failed to register and submit to government oversight. At least 145 people were wounded, officials said.
Protesters pushed through barbed wire and forced riot police to retreat inside the parliament complex.
The gunfire unfolded as the government pursues a broader attempt to regulate social media with a bill aimed at ensuring the platforms are “properly managed, responsible and accountable”.
The proposal has been widely criticised as a tool for censorship and for punishing government opponents who voice their protests online.
About two dozen social networks that are widely used in Nepal were repeatedly given notices to register their companies officially in the Himalayan nation, the government said.
