Police in Azerbaijan on Sunday detained opposition party leaders and dozens of their supporters before they were due to take part in a protest against the results of last week's national election.

The Musavat party said in a statement that its party leader Arif Gajily and REAL party leader Ilgar Mamedly, as well as opposition candidates and election observers, were among the 55 arrested demonstrators, some of whom were picked up near their homes.

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Dozens of riot police surrounded the Central Election Commission's (CEC) building, where the protest had been due to start from, and put anyone arriving to take part in the demonstration on a bus, a witness told Reuters news agency.

Protesters held up posters that read: "Abolish election results!" or "We demand free elections!"

Some of those detained were "taken in police vans to remote, deserted places 200-300km [120-180 miles] from Baku and abandoned there", Gadjily told AFP news agency after he was freed.

Police officials declined to comment on arrests, Reuters reported.

According to the CEC, the ruling Yeni Azerbaijan (New Azerbaijan) party won 72 out of 125 seats in the single-chamber Parliament in the February 9 vote, with nearly all other seats going to small parties and independents loyal to President Ilham Aliyev.

But international observers and the opposition denounced violations ranging from fraud to intimidation.

International monitors found widespread procedural violations in the vote count, which they said raised doubt about the honesty of the election. Aliyev had called the election nine months early to consolidate his authority and speed economic reforms.

The CEC has so far cancelled the results in four election constituencies following reports about violations.

Azerbaijan has been governed by Aliyev since 2003 when he succeeded his late father, Azerbaijan's Soviet-era Communist leader and former KGB general Heydar Aliyev.

Western nations have courted Azerbaijan because of its role as an alternative to Russia in supplying oil and gas to Europe, but various European bodies and rights groups have accused Aliyev of muzzling dissent and jailing opponents, charges Baku denies.