Myanmar officials have freed a leading dissident Buddhist monk after a brief detention, his monastery said, following a call from the United States for his immediate release.

Gambira was taken away by authorities early on Friday and released that night, less than a month after he was freed from a jail term for his leading role in mass anti-government protests in 2007.

He was one of hundreds of political prisoners released in January, cutting short a 68-year jail term imposed for his key role in the 2007 "Saffron Revolution", which was brutally crushed by the former junta.

Since he was freed, Gambira has breached regulations by breaking into monasteries closed by the government after the mass monk-led demonstrations, a government official told AFP Friday on condition of anonymity.

After questioning he was taken to senior monks who reprimanded him for his behaviour, according to the abbot at Maggin monastery in Yangon, where Gambira is staying.

"He was released by authorities last night after the senior monks spoke to him," abbot Einda Ka told AFP on Saturday.

After he was detained the United States said Myanmar's authorities, who have recently impressed the West with reformist moves, should release Gambira immediately.

State Department spokeswoman Victoria Nuland said that given the "government's stated commitment to reform and democratisation, we call on Burmese authorities to protect the fundamental freedoms of all its citizens, including all of those recently released from detention".

Myanmar's release of about 500 political prisoners since October has been hailed by Western countries, which have long demanded the freeing of such detainees before they would consider lifting sanctions.

A quasi-civilian regime, which came to power in March last year after almost half a century of outright military rule, has surprised critics with its apparent desire to reform and open up to the outside world.