YANGON, Myanmar (AP) — Demonstrators who protested peacefully in Yangon against a mining project in northwestern Myanmar have been charged under a law that denies them release on bail, a lawyer said Tuesday.

Aung Thein, the lawyer for two of the six activists arrested last week in Yangon, said they were accused of inciting unrest, a criminal offense that carries a maximum sentence of two years’ imprisonment. Their trial began Monday.

Aung Thein said authorities could have charged them under the peaceful assembly act, which permits bail. That act allows street protests if a permit is obtained.

Last Thursday, police cracked down on protesters occupying part of the Letpadaung copper mine, which critics say causes environmental and social damage. Dozens of protesters, including Buddhist monks, suffered burns from an incendiary riot-control device.

The crackdown was the biggest use of force against demonstrators since the reformist government of President Thein Sein took office last year.

The actions suggest the government is still unsure where it should draw the line on public protests. Thein Sein’s government has been hailed for releasing hundreds of political prisoners and for implementing laws allowing public demonstrations and labor strikes, though with some limitations.

At the same time, the government is anxious for foreign investment to expand an economy that was moribund during almost five decades of military rule. Government ministers have warned that to stop operations of the mine — a joint venture between an army company and a Chinese firm — would undermine the confidence of foreign investors.

Criticism of the violence against the monks, who are held in high regard, has complicated the issue. Militant monks in northern Myanmar are demanding an apology beyond the expressions of regret given by police to elder monks not involved in the incident.

Many in Myanmar also remain suspicious of the military and regard China as an aggressive and exploitative investor that helped maintain its rule.

At least three more activists outside the region of the mine have been arrested in the past few days.

On Saturday, police arrested a prominent former activist monk, Shin Gambira, his mother said. Gambira, whose lay name is Nyi Nyi Lwin, played a prominent role in 2007 pro-democracy demonstrations until he was arrested. He was released as part of an amnesty in January. The reason for his new detention is unclear.

Two other activists were arrested Sunday during a protest over the crackdown at the mine.

The government on Monday changed the tasks of a special commission led by opposition leader Aung San Suu Kyi that was to investigate the violent dispersal of the protesters at the mine and advise whether the mine project should continue.

The reformed commission will only assess the copper mine project, whether it will benefit the state and the people, and its social and environmental impact. The crackdown is no longer in its purview.

The commission’s membership was also reduced from 30 to 16. Two of those dropped, prominent former student activists Min Ko Naing and Ko Ko Gyi, had already withdrawn, saying they wanted to conduct an independent investigation.

Suu Kyi’s appointment to head the probe should lend it credibility, as she is highly popular for her long fight against military rule.

She visited the mine area in the wake of the crackdown, meeting with mining company officials, activists and injured protesters, as well as security officials. In speeches to area residents, she said the use of force in the crackdown was not justified, but also suggested that protesters might have to compromise on the mine issue because Myanmar needed to honor its contracts, even if they were made under the previous military regime.