Myanmar's junta announced on Sunday 1 October that it had begun a pilot census in 20 townships in Karen, Bago, and Mandalay regions, a move critics say will be used to increase surveillance of opponents.

The military has justified its 2021 coup with unsubstantiated claims of widespread fraud in 2020 elections won resoundingly by civilian leader Aung San Suu Kyi's National League for Democracy (NLD).

Junta officials have said a national census must be completed before fresh elections, which the government has hinted may come in 2025.

"We will conduct [a census] from 1-15 October 2023, in 20 townships selected in Naypyidaw and other states and regions," the statement said, referring to the military-built capital but without specifying which areas would be involved.

"These 20 townships will be a sample," it said.

State media reported the pilot had started in the Karen, Bago, and Mandalay regions.

There was no indication from the military where in those areas, which have all seen recent fighting between the junta and its opponents, the pilot would take place.

It comes ahead of a nationwide census in 2024, state media said.

Critics say the junta will use the census to step up monitoring of opponents of its coup, including thousands of civil servants, doctors and teachers who have not returned to work in protest.

The Southeast Asian country remains deeply divided by conflict, with civilians caught up in near-daily bomb blasts and fighting. The military has acknowledged it does not fully control certain areas.

More than 1.6 million people are also currently displaced by the violence that has riven the country since the coup, according to the United Nations.

The United States has said any elections under the junta would be a "sham", while analysts say polls would be targeted by the military's opponents and spark further bloodshed.

Russia has said it backs the generals' plan for polls and its election commission signed a memorandum on "cooperation in election activities" with Myanmar last month.

While there was no mention of it in the statement, Myanmar has said it intends to roll out an electronic identification system.

Officials said the scheme will collect "biographic data and the biometric data of citizens aged 10 years and above".

Ministers asked China -- a major ally, arms supplier and operator of a sprawling internal surveillance network -- for help last month implementing the programme.