(Updates with lawyer's denial of Suu Kyi release rumour)
* Suu Kyi's lawyer says he is unable to see her
* Civil disobedience campaign grows against military rule
* Blinken presses Chinese counterpart to condemn coup
* Australia summons Myanmar ambassador
Feb 6 (Reuters) - Tens of thousands of people took to the streets of Myanmar's cities on Saturday to denounce this week's coup and demand the release of elected leader Aung San Suu Kyi despite a blockade on the internet by the junta.
In an upwelling of anger in the country's largest city, Yangon, protesters chanted, "Military dictator, fail, fail; Democracy, win, win" and held banners reading "Against military dictatorship". Bystanders offered them food and water.
Late in the evening, a rumour of Suu Kyi's release - quickly denied by her lawyer - triggered noisy street celebrations.
Cheering and letting off firecrackers, residents said the message was shared by the military-run media Myawaddy. But Suu Kyi's lawyer Khin Maung Zaw denied that the 75-year-old leader had been freed and told Reuters she was still in detention.
Suu Kyi's National League for Democracy (NLD) won Nov. 8 elections in a landslide, a result the generals have refused to recognise, claiming fraud.
Earlier, thousands marched on Yangon's City Hall. Drivers honked horns and leaned out of their cars and raised the three-finger salute, a gesture returned by protesters. Some of them held up NLD flags or pictures of Suu Kyi and clapped and danced.
By evening, the protesters had mostly dispersed. But for a fifth night, a cacophony rose in the darkness as people banged on pots, pans and drums in a show of resistance even as power cuts affected many districts of the city.
Thousands more took to the streets in Myanmar's second city Mandalay and its military-built capital Naypyidaw, home to the nation's government servants, where demonstrators chanted anti-coup slogans and called for Suu Kyi's release.
The protests built despite a blockade of the internet imposed after demonstrators first began to gather. All day, the state-run broadcaster MRTV showed scenes praising the military.
Monitoring group NetBlocks Internet Observatory reported a "national-scale internet blackout", saying on Twitter that connectivity had fallen to 16% of usual levels.
The junta did not respond to requests for comment. It extended a social media crackdown to Twitter and Instagram after seeking to silence dissent by blocking Facebook , which counts half of the population as users.
Facebook urged the junta to unblock social media.
"At this critical time, the people of Myanmar need access to important information and to be able to communicate with their loved ones," Facebook's head of public policy for Asia-Pacific emerging countries, Rafael Frankel, said in a statement.
The United Nations human rights office said on Twitter that "internet and communication services must be fully restored to ensure freedom of expression and access to information."
Norwegian mobile network provider Telenor ASA said authorities had ordered all mobile operators to temporarily shut down the data network, although voice and SMS services remained open.
Myanmar civil society groups appealed to internet providers to resist the junta's orders, saying in a joint statement they were "essentially legitimising the military's authority".
Telenor said it regretted the impact of the shutdown on the people of Myanmar but said it was bound by local law and its first priority was the safety of its local workers.
Army chief Min Aung Hlaing seized power alleging fraud, although the electoral commission says it has found no evidence of widespread irregularities in the November vote.
The junta announced a one-year state of emergency and has promised to hand over power after new elections, without giving a timeframe.
Nobel Peace laureate Suu Kyi, has been charged with illegally importing six walkie-talkies, while ousted President Win Myint is accused of flouting COVID-19 restrictions. Neither has been seen since the coup. Their lawyer said they were being held in their homes.
NLD member Aung Moe Nyo, chief minister of the Magway region, said on Facebook before the shutdown: "It is not OK to let the country fall under junta government. I am very much thankful to those who oppose this, to those government staff who oppose this. This act is to save the country."
Sean Turnell, an Australian economic adviser to Suu Kyi, said in a message to Reuters on Saturday he was being detained.
Australia's government, without naming Turnell, said it had summoned the Myanmar ambassador to register "deep concern" over the arbitrary detention of Australian and other foreign nationals in Myanmar.
A civil disobedience movement has been building in Myanmar all week, with doctors and teachers among those refusing to work. Every night people bang pots and pans in a show of anger.
The protests in Yangon would resume on Sunday, demonstrators said. One, who asked not to be named, said: "We will go and protest again tomorrow. If they arrest one person, we will try to pile in and fill up the truck as a group."
The coup has sparked international outrage, with the United States considering sanctions against the generals and the U.N. Security Council calling for the release of all detainees.
It has also deepened tensions between the United States and China, which has close links to Myanmar's military. Secretary of State Antony Blinken pressed top Chinese diplomat Yang Jiechi in a phone call on Friday to condemn the coup, the State Department said.
The generals have few overseas interests vulnerable to sanctions but the military's extensive business investments could suffer if foreign partners leave - as Japanese drinks company Kirin Holdings said it would on Friday.
Suu Kyi spent 15 years under house arrest after leading pro-democracy protests against the long-ruling military junta in 1988.
After sharing power with a civilian government, the army began democratic reforms in 2011. That led to the election of the NLD in a landslide victory four years later. November's election was meant to solidify a troubled democratic transition.
(Reporting by Reuters staff; Writing by Matthew Tostevin, Grant McCool and Stephen Coates; Editing by William Mallard and Ros Russell)
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