(Adds U.N. Security Council to discuss, rights chief, U.S. Senate Republican leader comments)
* Army declares one-year state of emergency
* Military takeover condemned internationally
* Suu Kyi's party won November election in landslide
* Military alleges election marred by fraud
Feb 1 (Reuters) - Myanmar's military seized power on Monday in a coup against the democratically elected government of Nobel laureate Aung San Suu Kyi, who was detained along with other leaders of her party in early morning raids.
Western nations condemned the sudden turn of events, which derailed years of efforts to establish democracy in the poverty-stricken country and raised even more questions over the prospect of returning a million Rohingya refugees.
The U.N. Security Council will meet on Tuesday, diplomats said, amid calls for a strong response.
The army said it had responded to "election fraud", handing power to military chief General Min Aung Hlaing and imposing a state of emergency for a year in the country, also known as Burma, where neighbouring China has a powerful influence.
The generals made their move hours before parliament had been due to sit for the first time since the National League for Democracy's (NLD) landslide win in a Nov. 8 election viewed as a referendum on Suu Kyi's fledgling democratic rule.
The NLD said Suu Kyi had called on people to protest against the military takeover, quoting comments it said had been written in anticipation of a coup.
Phone and internet connections in the capital, Naypyitaw, and the main commercial centre Yangon were disrupted and state television went off air after the NLD leaders were detained.
Summarising a meeting of the new junta, the military said Min Aung Hlaing, who had been nearing retirement, had pledged to practice a "genuine discipline-flourishing multiparty democratic system".
He promised a free and fair election and a handover of power to the winning party, it said, without giving a timeframe.
The junta later removed 24 ministers and named 11 replacements to oversee ministries including finance, defence, foreign affairs and interior.
Suu Kyi, President Win Myint and other NLD leaders were "taken" in the early hours of the morning, NLD spokesman Myo Nyunt told Reuters by phone. U.N. human rights chief Michelle Bachelet said at least 45 people had been detained.
A video posted to Facebook by one MP appeared to show the arrest of regional lawmaker Pa Pa Han. Her husband pleads with men in military garb standing outside the gate. A young child can be seen clinging to his chest and wailing.
Troops and riot police stood by in Yangon where residents rushed to markets to stock up on supplies and others lined up at ATMs to withdraw cash. Banks suspended services but said they would reopen from Tuesday.
Foreign companies from Japanese retail giant Aeon to South Korean trading firm POSCO International and Norway's Telenor scrambled to reach staff in Myanmar and assess the turmoil.
Multinationals moved into the country after Suu Kyi's party established the first civilian government in half a century in 2015.
The Nobel Peace Prize laureate's election win followed decades of house arrest and struggle against the military, which had seized power in a 1962 coup and stamped out all dissent for decades.
While still hugely popular at home, her international standing was severely damaged after she failed to stop the expulsion of hundreds of thousands of Rohingyas in 2017.
The detentions came after days of tension between the civilian government and the military in the aftermath of the most recent election, in which Suu Kyi's party won 83% of the vote.
An army takeover would put Myanmar "back under a dictatorship", the pre-written statement on Facebook quoted Suu Kyi as saying.
"I urge people not to accept this, to respond and wholeheartedly to protest against the coup by the military," it said. Reuters was unable to reach any NLD officials to confirm the veracity of the statement.
Supporters of the military celebrated the coup, parading through Yangon in pickup trucks and waving national flags.
"Today is the day that people are happy," one nationalist monk told a crowd in a video published on Facebook.
Democracy activists and NLD voters were horrified and angry. Four youth groups condemned the coup in statements and pledged to "stand with the people" but did not announce specific action.
"Our country was a bird that was just learning to fly. Now the army broke our wings," student activist Si Thu Tun said.
Senior NLD leader Win Htein said in a Facebook post the army chief's takeover demonstrated his ambition rather than concern for the country.
In the capital, security forces confined members of parliament to residential compounds on the day they had expected to take up their seats, representative Sai Lynn Myat said.
'POTENTIAL FOR UNREST'
The United Nations led condemnation of the coup and calls for the release of detainees and restoration of democracy in comments largely echoed by Australia, Britain, the European Union, India, Japan and the United States.
"The military must reverse these actions immediately," U.S. Secretary of State Antony Blinken said, while Senate Republican leader Mitch McConnell called on Joe Biden's new Democratic administration to respond strongly.
In Japan, a major aid donor with many businesses in Myanmar, a ruling party source said the government may have to rethink the strengthening of defence relations with the country undergone as part of regional efforts to counterbalance China.
China called on all sides in Myanmar to respect the constitution and uphold stability in a statement which "noted" events in the country rather than expressly condemning them.
Bangladesh, which is sheltering around one million Rohingya who fled violence in Myanmar, called for "peace and stability" and said it hoped a process to repatriate the refugees could move forward. Rohingya refugees in Bangladesh also condemned the takeover.
The Association of Southeast Asian Nations, of which Myanmar is a member, called for "dialogue, reconciliation and the return to normalcy" while in Bangkok, police clashed with a group of pro-democracy demonstrators outside Myanmar's embassy.
"It's their internal affair," a Thai government official said of events in Myanmar - a hands-off approach also taken by Malaysia and the Philippines.
The November vote faced some criticism in the West for disenfranchising many Rohingya but the election commission rejected military complaints of fraud.
In its statement declaring the emergency, the military cited the failure of the commission to address complaints over voter lists, its refusal to postpone new parliamentary sessions, and protests by groups unhappy with the vote.
"Unless this problem is resolved, it will obstruct the path to democracy and it must therefore be resolved according to the law," the military said, citing an emergency provision in the constitution in the event sovereignty is threatened.
(Reporting by Reuters staff; writing by Stephen Coates, Robert Birsel and Philippa Fletcher; editing by Lincoln Feast, Angus MacSwan and Grant McCool)