Confirming reports of protesters’ deaths has been difficult amid the chaos and general lack of news from official sources.
Uncertainty has grown over detained elected leader Aung San Suu Kyi's whereabouts, with local media reporting she had been moved from house arrest to an undisclosed location.
Students had pledged to join the daily protests and strikes that have been ongoing for roughly three weeks, but police blocked the gates of the campus.
Crowds in the country's biggest city, Yangon, gathered after supporters of the Civil Disobedience Movement called for people to unite on Monday.
At least five people were injured by rubber bullets and had to be carried away in ambulances, according to an Associated Press journalist who witnessed the violence.
Despite junta appeals for civil servants to return to work and threats of actions if they do not, there has been no sign of the strikes easing.
The military seized power on Feb. 1, the day newly elected parliamentarians were supposed to take their seats.
The protests are taking place in defiance of an order banning gatherings of five or more people.
Demand for VPNs has soared, allowing some people to evade the ban, but users reported more general disruption to mobile data services that most rely on for news and communications.
Win Htein, 79, is a longtime confidante of the ousted leader Aung San Suu Kyi and had publicly called for civil disobedience in opposition to Monday's coup.