Dozens of legislators have walked out of the inaugural session of Algeria's parliament to protest what they say was an election rigged to hand a majority to the ruling elite's party.
Saturday's walk-out saw 49 legislators from the Green Algeria Alliance (AVV) along with MPs from two smaller parties, who combined hold 60 of the 462 seats in the parliament, boycott the first meeting of the chamber since a May 10 election.
The parliamentarians held up placards reading "No to fraud!" before leaving the session immediately after the roll-call of newly-elected deputies.
Condemning "a return to the era of single party rule", the AVV said in a statement: "We decided to withdraw from the first session of the National Assembly and protest officially against the results of the ballot".
Lakhdar Benkhelaf of the Islamist Front for Justice and Development, one of the parties in the Political Front for the Safeguard of Democracy, said the boycott of parliament was "a question of principle".
It was not clear if the members of parliament who walked out would later return.
For Algeria, the only country in North Africa left largely untouched by last year's so-called "Arab Spring" revolts, a prolonged boycott by the MPs could complicate a reform of the constitution which President Abdelaziz Bouteflika has promised for this year.
Constitutional amendments require the support of three-quarters of parliament. A boycott by the groups who staged the walk-out, holding roughly 13 per cent of the seats in the chamber, could make it more difficult to cross the threshold for changes to the constitution.
In the May 10 election, the National Liberation Front (FLN) - Algeria's ruling party since independence from colonial ruler France half a century ago - won 220 seats, and the allied RND party came second with 68 seats.
The AVV, which had confidently predicted victory in the election, alleged fraud after it won fewer than 50 seats.
The result was at odds with the trend elsewhere in North Africa, where uprisings have pushed out entrenched leaders and handed power to once-outlawed religiously-minded political groups.
Algeria's Islamist parties failed to inspire much enthusiasm in this month's election, however.
Their leaders have long-standing links to the ruling establishment and many people were sceptical they represented a genuine opposition force.
One specialist on Islamist politics said anger over the election could give the parties a momentum they lacked before the election.
"This could be a mistake [for the authorities] because it may unify the Islamists who are very divided now," Mohamed Mouloudi told the Reuters news agency.
Algerian officials deny any manipulation of the election result, and European Union observers, who monitored the vote, did not offer any evidence of ballot fraud.