The UN human rights office said on Friday it is concerned the military in Myanmar could be preparing an imminent attack aimed at its opponents amid a build-up of heavy weapons and troops in areas of the country where theInternet has also been shut down.

Ravina Shamdasani, UN human rights spokeswoman, said that it had documented intensifying attacks by the army in the past month in Chin state and other areas, with killings and burning of houses, in an apparent attempt to seek out armed resistance.

“What has happened now over the past few days, we have seen a real reinforcement, a substantial deployment of heavy weapons and troops in these areas,” Shamdasani told a UN briefing.

The violence and build-up have led to the office of UN rights chief Michelle Bachelet becoming “very alarmed and concerned that there may be an imminent attack”.