Security forces in Myanmar pointed guns toward anti-coup protesters and attacked them with sticks on Monday, seeking to quell the large-scale demonstrations calling for the military junta that seized power earlier this month to reinstate the elected government.

More than 1,000 protesters rallied in front of the Myanmar Economic Bank in Mandalay, the country’s second-largest city, when at least 10 trucks full of soldiers and police arrived and immediately started firing slingshots toward the protesters, according to a photographer who witnessed the events.

The soldiers and police then attacked the protesters with sticks, and police could be seen aiming long guns into the air amid sounds that resembled gunfire. Local media reported that rubber bullets were also fired into the crowd, and that a few people were injured.

Police were also seen pointing guns toward the protesters.

In the capital, Naypyitaw, protesters gathered outside a police station demanding the release of a group of high school students who were detained while joining in anti-coup activities.

One student who managed to escape told reporters that the pupils — thought to range in age from 13 to 16 — were demonstrating peacefully when a line of riot police suddenly arrived and began arresting them. It wasn’t clear exactly how many students were rounded up, but estimates put the figure at between 20 and 40.

Earlier Monday, Myanmar’s military leaders extended their detention of deposed leader Aung San Suu Kyi, whose remand was set to expire and whose freedom is a key demand of the crowds of people continuing to protest the Feb. 1 coup.

Suu Kyi will now be remanded until Feb. 17, when she will likely appear in court by videoconference, according to Khin Maung Zaw, a lawyer asked by Suu Kyi’s party to represent her. The Nobel laureate remains under house arrest on a minor charge of possessing unregistered imported walkie-talkies.

Suu Kyi’s extended detention is likely to further inflame tensions between the military and the protesters who have taken to the streets of cities across the Southeast Asian nation seeking the return of the government they elected.