GENEVA (Reuters) - Violence in Kyrgyzstan appears to have begun with five coordinated attacks and has taken on an inter-ethnic character that could spiral out of control, the U.N. human rights office warned on Tuesday.

The office of U.N. High Commissioner for Human Rights Navi Pillay has collected eyewitness accounts, including from U.N. staff, in the southern Kyrgyz cities of Osh and Jalalabad, her spokesman Rupert Colville said.

“We have strong indications that this event was not a spontaneous inter-ethnic clash -- that it was to some degree orchestrated, targeted and well-planned,” Colville told a news briefing in Geneva.

“Several of these reports suggest that the incident began with five simultaneous attacks in Osh involving men wearing balaclavas and carrying guns. It looked like they were seeking to provoke a reaction,” he said.

Colville said that one of the attacks was on a gym which he said was “known to be the haunt of a criminal gang” in Osh. “Targeting that gym was likely to provoke a reaction.”

“So it might be wrong to cast it, at least in origin, as an inter-ethnic conflict. There seems to be other agendas driving it initially. But once it start to take off on ethnic lines, then of course you start to get a clear divide and tit-for-tat reactions which is what’s so particularly dangerous,” he said.

At least 176 people have been killed in the violence which erupted in the Central Asian state last Thursday and may soon have driven 100,000 refugees across the border to Uzbekistan.

The interim government, which assumed power after the president was overthrown in April, has accused supporters of the ousted president, Kurmanbek Bakiyev, of stoking ethnic conflict. Bakiyev, who is in exile in Belarus, has denied this allegation.

The U.N. human rights office was not in a position to make any direct accusations against any particular individuals or groups at this point, according to Colville.

“It is very hard to confirm anything properly at this point, it is so fluid, and so volatile and so insecure,” he added.

But it is an “extremely dangerous situation given the ethnic patchwork in this part of Kyrgyzstan,” he said, noting there were some 80 different groups in the Osh area alone.

“Clearly the most important thing is that the violence stops....Inter-ethnic conflicts, once they start to spiral out of control, can really become very, very hard to rein in.”

Separately, independent U.N. rights investigators called for restraint and dialogue, and voiced deep concern at reports of a shoot-to-kill policy adopted by the provisional government.

“Force should be used by law enforcement officials only when strictly necessary, and that force must be in proportion to the legitimate objective to be achieved,” they said in a statement.

“It is essential to quickly establish the rule of law and to establish long term measures to promote dialogue and improve relations between ethnic groups,” they added.

The joint statement was issued in Geneva by Kay McDougall, independent expert on minority issues, Philip Alston, special rapporteur on executions, and Githu Muigai, rapporteur on racism and racial discrimination, xenophobia and related intolerance.