Rival parliaments are meeting in Kyrgyzstan amid rowdy scenes and confusion over who has the right to be part of the interim government.
Arguments break out in the assembly building in Bishkek
The country's electoral body on Sunday backed the parliament elected in February's disputed polls that led to the removal of President Askar Akayev.
On Thursday, the Supreme Court annulled the polls and said the previous parliament had authority.
The acting president, Kurmanbek Bakiev, supports the court ruling.
However, the new head of security, Felix Kulov, told deputies gathered in the capital, Bishkek, that the term of the old parliament had expired and that legally, the new parliament was legitimate.
The BBC's Ian MacWilliam says most of those present were newly elected deputies.
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But some members of the outgoing legislature complained loudly, shouting that people who had won their seats in "rigged" elections should not be taking part.
The Supreme Court said in its ruling to annul the polls that they had been widely discredited by government interference.
Some speakers on Sunday said that both bodies should be disbanded.
Our correspondent says the apparent disagreement between the acting president and the acting security head could foreshadow further disagreements between the two most influential leaders of the opposition groups who now run the country.
Mr Bakiev has announced that presidential elections will take place on 26 June.
However, Europe's key security body has opposed the plan.
Markus Mueller, the Organisation for Security and Co-operation in Europe (OSCE) envoy to Kyrgyzstan, said: "I don't believe this [date] is realistic because it's a very short period of time. There are still a lot of questions unresolved - constitutional questions."
The envoy would not give a date when he thought elections could be held, saying talks with the rival parliaments and powerful clans would be necessary.
"If it does not become quieter, elections will just add to the instability," he said.
Mr Akayev was ousted amid large-scale demonstrations following the disputed parliamentary elections.
It remains unclear where the former president is, but many observers say he is probably in Russia.
Russia says it has offered to host Mr Akayev, at his own request.
Mr Akayev has accused the opposition of staging an "anti-constitutional coup".
The US and Russia vie for influence in Kyrgyzstan, a former Soviet state bordering China, with each holding a military base outside Bishkek.