* Political unrest rocks Kyrgyzstan after parliamentary election
* Western observers said vote marred by vote buying
* Opposition supporters seize government buildings
* President says a coup d'etat is underway
(Adds nomination of Zhaparov as interim PM in paragraph 18)
By Olga Dzyubenko and Vladimir Pirogov
BISHKEK, Oct 6 (Reuters) - Opposition groups took control of most of Kyrgyzstan's government apparatus on Tuesday after storming buildings during post-election protests, but the president clung to power as unrest risked tipping the Central Asian state into chaos.
Protests spread throughout the country, where two presidents have been overthrown in the past 15 years, halting some foreign gold mining operations and prompting an expression of concern from Russia, a longtime ally.
President Sooronbai Jeenbekov called for calm and ordered security forces not to open fire on protesters after unrest in which one person had been killed and 686 wounded by Tuesday afternoon, according to the health ministry.
Officials said Sunday's parliamentary election, which protesters condemned as illegitimate, would be rerun, while the opposition took charge of the key post of parliament speaker.
Fresh clashes remained a serious risk however, as protesters stayed on the streets and a crowd armed with rocks and stones broke into a hotel where members of parliament had convened, forcing the newly proposed interim prime minister, an opposition figure, to flee, according to a report by news website Akipress.
Shop owners in the capital Bishkek, fearing looting, installed metal shields against marauders.
Burnt-out cars littered the city after protesters stormed the main government building, known as the White House, early on Tuesday. It briefly caught fire before emergency services put out the blaze and debris from inside, including government papers, and office furniture, was strewn outside.
Kyrgyzstan, which borders China, has long been a platform for geopolitical competition between Moscow, Washington and Beijing. It houses a Russian military base and its leaders and main opposition groups have traditionally backed close ties with Russia.
Yet unidentified intruders torched a Russian-operated factory at Kyrgyzstan's second-largest gold deposit Jeruy on Tuesday, forcing its owners to suspend development of the site.
Russia's military base was put on high alert.
London-listed miner Kaz Minerals KAZ.L said it had suspended production at its Bozymchak copper and gold mine and protesters showed up at smaller mines developed by Chinese and Turkish companies and demanded they halt operations, according to local news website Akipress.
State-owned gold miner Kyrgyzaltyn said it had repelled an attempted attack on its office. Another group appeared to have broken into its gold refinery.
Canada's Centerra Gold CG.TO , which operates the country's biggest gold deposit, said its operations were continuing uninterrupted.
GOVERNMENT TAKEOVER
The opposition said it had set up a coordination council and was discussing the line-up of a provisional government.
Opposition groups also freed Almazbek Atambayev, a former president jailed on corruption charges after falling out with Jeenbekov. Atambayev was not named to any role, however, and Jeenbekov showed no immediate signs of relinquishing power.
The central election commission said it had annulled the results of the election and a new one would be called shortly.
Following calls to legitimise a transfer of power, the outgoing parliament elected opposition politician Myktybek Abdyldayev as speaker.
It also proposed Sadyr Zhaparov as interim prime minister, online media outlet 24.kg quoted Abdyldayev as saying on Tuesday evening. Other media previously reported that he was elected as interim prime minister. sprang Zhaparov earlier in the day from a prison where he was serving a sentence on charges of hostage-taking in 2013 unrest.
Interior Minister Kashkar Junushaliyev did not show up for work on Tuesday, a ministry spokesman said, saying that Kursan Asanov, an opposition politician and a former senior security official, had taken over as acting interior minister.
The Russian embassy said it supported resolving the situation in the country through legal means while ensuring stability and people's safety.
CONTESTED VOTE
Trouble erupted on Monday after police used teargas and water cannon to disperse thousands of people demanding the election be annulled. observers said the election, which appeared to have handed most seats to two establishment parties supporting closer links between the former Soviet republic and Russia, had been marred by vote buying. of the parties was close to Jeenbekov, who insisted in an interview with the BBC on Tuesday night that he remained the legitimate president and that it was his job to consolidate the positions of various factions through negotiations.
As well as storming the White House, which houses both the president and parliament, protesters took over several other buildings, including the mayor's office.
They appointed their own acting head of national security, acting prosecutor general and a commandant of Bishkek, although it was hard to judge how much power they wielded. (Writing by Olzhas Auyezov; Editing by Andrew Osborn, Philippa Fletcher and Giles Elgood)