Buddhist monks who suffered severe burns during a police crackdown on protesters campaigning against a Chinese-backed copper mine two years ago have launched a lawsuit against Burma's home affairs minister.

More than 100 Buddhist monks suffered severe burns from smoke bombs that reportedly contained white phosphorous when police dispersed the protesters at the Wanbao Mining Copper Ltd.

Justice Trust, a human rights group that works to advance rule of law in Burma and is supporting the monks, said the lawsuit was launched against home affairs minister General Ko Ko for ordering what it called an illegal police action.

It said 57 of the injured monks suffered serious burns requiring long-term medical care.

The Letpadaung mine - a joint venture between a Burmese military-controlled holding company and China's Wanbao Mining Copper Ltd, a unit of weapons manufacturer China North Industries Corp - has been a focal point of land rights disputes in recent years.

The protest in November 2012 drew international attention.

Last December, a villager was shot dead during a confrontation as police and Chinese workers erected a fence on land that villagers claimed was theirs.