A yearlong state of emergency was announced in Myanmar after the detention of senior government leaders on Monday.

A declaration signed on Monday morning by First Vice-President U Myint Swe, a former general who is serving as acting president, and announced on the military-owned Myawaddy TV, also stated that state power is being handed over to Commander-in-Chief of Defence Services Min Aung Hlaing.

After two months of disputes over November's election results, the Myanmar military said in a televised statement, "After the state of emergency period, free and fair multiparty general elections will be rerun and the state power will be handed over to an elected party which meets the democratic standards."

As its longtime friendly neighbor, China hopes that all sides in Myanmar will "safeguard political and social stability" while handling their differences properly within the framework of the Constitution and the law, Foreign Ministry spokesman Wang Wenbin said at a news briefing on Monday.

Shortly before the declaration, Myo Nyunt, a spokesman for the ruling National League for Democracy, said Myanmar's State Counsellor Aung San Suu Kyi, President U Win Myint and other senior officials were detained by the military.

The first regular session of the country's parliament since the November elections was scheduled to begin on Monday in order to elect top government leaders.

In November, Suu Kyi's NLD secured a landslide election victory, winning over 80 percent of the contested seats. The military has an unelected quota of 25 percent of parliamentary seats.

But the military had refused to recognize the election results, alleging massive voting fraud. The Union Election Commission dismissed the allegations last week.

The military said in the televised statement that the commission failed to resolve irregularities regarding the November election, and had declined to call a special meeting of the previous parliament, which was requested by the military and the Union Solidarity and Development Party.

Myanmar Defence Forces spokesman Zaw Min Tun warned on Jan 26 that it could "take action "if the election dispute remained unresolved.

On Saturday, a statement issued by the military said "if the Constitution is not obeyed, it must be revoked", the Myanmar Times reported.

Since its independence from British colonialism in 1948, Myanmar has twice revoked its Constitution, in 1962 and 1988, when the military took power.

Soldiers were seen on the streets of the capital city, Naypyitaw, and the former capital, Yangon, on Monday. Many residents lined up for food and other necessities as state-run radio and television were off air for a time due to "communication difficulties".

"We will see pressure from the international community" on the military, said Alistair D.B. Cook, a senior fellow at the Centre for Non-Traditional Security Studies of Nanyang Technological University's S. Rajaratnam School of International Studies in Singapore.

United Nations Secretary-General Antonio Guterres and the governments of nations including the United States, Australia and Japan expressed concern over the situation in Myanmar in statements released on Monday.

Xinhua and agencies contributed to this story.