Repatriations of Rohingya refugees will begin on schedule by Jan. 22, Myanmar said Thursday, as the United Nations and rights groups cast concern over the process.

Some 655,000 minority Rohingya have fled Myanmar's northern Rakhine State to Bangladesh following a military crackdown, labeled ethnic cleansing by the U.N., launched in August last year.

Refugees would begin returning in line with an agreement signed by the two countries in November, Myanmar's minister for social welfare, relief and resettlement, Win Myat Aye, told German Press Agency (DPA).

The people would return to their original villages after being housed at a "temporary area," he said.

Hundreds of Rohingya villages have been burned in Rakhine state since August, according to analysis of satellite imagery by Human Rights Watch (HRW).

The U.N. would be involved "at some stage" in the repatriations, in accordance with the agreement, the minister said.

A spokesperson for the U.N. High Commissioner for Refugees said Wednesday that returns should not be premature and that "further measures" were required to ensure their safety in Myanmar.

Myanmar's government is in "la la land" if it believes Rohingya would return in line with the minister's schedule, warned Phil Robertson, deputy Asia director at Human Rights Watch.

"Why in the world would they dare go back within arm's length to the army that just systematically shot, raped and murdered them, and torched their homes?" he asked DPA on Wednesday.