Key aide of Myanmar's Suu Kyi arrested

U Win Htein, patron of Myanmar's National League for Democracy, or NLD, was arrested late on Thursday, an official from the Myanmar Police Force said on Friday.

The 80-year-old, who is believed to be a trusted confidant of the party's chairwoman Aung San Suu Kyi, was taken to a district police station in Nay Pyi Taw soon after his arrival in Yangon from the national capital on Thursday, Kyi Toe, a member of the party's information committee, wrote on his social media account earlier.

The arrest of U Win Htein comes after President U Win Myint and State Counselor Aung San Suu Kyi were remanded in custody, until Feb 15, under the charge of violating the National Disaster Management Law and Import-Export Law, according to a senior military official.

The president and the state counselor were detained by the military, along with other NLD officials, early on Monday.

Myanmar declared a one-year state of emergency with power handed over to the Commander-in-Chief of Defense Services, Senior General Min Aung Hlaing, according to a statement from the military.

On Thursday, the United Nations Security Council voiced "deep concern" over the situation in Myanmar.

The 15-member council released a statement stressing the "need to uphold democratic institutions and processes, refrain from violence, and fully respect human rights, fundamental freedoms and the rule of law".

A spokesperson for the Chinese UN mission said any action by the UN Security Council should be conducive to the political and social stability, peace and reconciliation in Myanmar.

Describing Myanmar as "a friendly neighbor", the spokesperson expressed China's hope that all parties in the nation prioritize the aspiration and interests of its people, handle differences through dialogue within the constitutional and legal framework, as well as safeguard political and social stability.

Xinhua, Liu Yinmeng in Los Angeles and agencies contributed to this story.