* Days of protests about power cuts tolerated until now
* Government has announced measures to address problem
* ASEAN chief calls for calm
* China says protests not about its electricity imports
By Aung Hla Tun
YANGON, May 24 (Reuters) - Myanmar police broke up a demonstration against power cuts by hundreds of people in the town of Pyi on Thursday and briefly held five people for questioning as protesters tested the limits of democratic changes for a fifth day.
Among those detained in Pyi was a member of Aung San Suu Kyi’s National league for Democracy (NLD) party and four activists from a human rights organisation, who were later freed, NLD officials and members said.
Several NLD members were also detained in the early hours in the city of Mandalay, where protests over electricity outages started on Sunday before spreading to several urban centres, including the commercial capital, Yangon.
The protests come as citizens, including some workers on strike over pay in industrial zones in Yangon, test the boundaries of broad changes that have taken place in the past year in Myanmar.
Until now, security forces have allowed the peaceful demonstrations to go ahead and the civilian government, which took over from a repressive junta in March last year and has eased restrictions on demonstrations, has promised emergency measures to increase the electricity supply.
“So far as I heard from our members in the region, there was a protest of about 400 people at least,” NLD official Nyan Win said, referring to the area around Pyi, about 260 km (160 miles) northwest of Yangon.
Ba Shi, an NLD member in Pyi said five people were freed in the afternoon after brief detention at a prison, where a crowd had assembled to demand their release.
Tint Swe, an NLD committee member in Mandalay, told Reuters that he and two other party members were picked up by police at around 5 a.m. (2230 GMT on Wednesday) and questioned about who was behind the protests. They were treated well and taken home about five hours later, he said.
State television said on Wednesday six generators bought from U.S. firm Caterpillar Inc would be air-freighted within a week and two 25-megawatt gas turbines would be bought from General Electric Co to tackle the power shortage.
Urgent repairs would be carried out on power stations damaged in fighting with ethnic Kachin rebels, it added.
For decades, military authorities crushed protests against their rule, which often began because of frustration over bread-and-butter issues. The biggest and bloodiest uprisings against military rule, in 1988 and 2007, were sparked by economic grievances including soaring prices.
The head of the Association of Southeast Asian Nations (ASEAN), of which Myanmar is a member, said the authorities should avoid violence and resist any temptation to suppress dissent.
“If a country or society aspires to open to democracy, it has to be prepared to deal with popular participation, pressure, demand, conflicts, tension, in some cases violence,” Surin told Reuters in an interview in Tokyo. “But a country or a government will need to deal with it.”
This week’s marches pose a problem for reformist President Thein Sein - himself a former junta general - who has freed hundreds of political prisoners, relaxed state censorship, started peace talks with ethnic rebels and held by-elections that put Nobel Peace Prize laureate Suu Kyi in parliament.
But the political and economic reforms are likely to raise expectations that both the government and the opposition led by Suu Kyi might struggle to meet.
Heavy-handed tactics to end the protests would be seized upon by government critics sceptical about the reforms, while the authorities will worry the demonstrations could spread.
The disturbances come as Suu Kyi, who spent 15 years in detention under the junta, is planning her first foreign trip in 24 years with a visit to Thailand next week for an economic conference. Under military rule, she refused to leave Myanmar, afraid she would not be allowed back.
The demonstrations are also taking place as employees of about 10 firms in industrial zones around Yangon have held strikes over pay and labour rights.
It was not clear if the protests over power cuts would fizzle or blow up into a broader show of dissatisfaction.
Some residents in Mandalay and Yangon said the power supply had improved there on Wednesday night, although activist Ko Htin Kyaw, 49, said Yangon suburbs were still experiencing outages.
“We have to wait and see whether they are as good as their word. This is not the first time they’ve said that,” he said.
The protesters accuse members of the former junta of enriching themselves at the public’s expense by selling natural gas to neighbouring China while Myanmar, among Asia’s poorest nations, faces frequent power outages.
Chinese Foreign Ministry spokesman Hong Lei told reporters in Beijing electricity deals involving Chinese firms were legal and protesters’ anger was directed at Myanmar’s overstretched power grid rather than China’s energy imports.
Hong said China was willing to help Myanmar improve its power grid. Consumption in Myanmar, where only 25 percent of the population has access to the national grid, is one of the lowest in the world, averaging 104 kilowatts an hour per person, near the same level as the Democratic Republic of Congo and Nepal, according to the World Bank and Asian Development Bank.