Aziz Karimov, Associated Press
A woman leaves a voting cabin to cast her ballot at a polling station during a parliamentary elections in Baku, Azerbaijan, Sunday, Nov. 1, 2015. Voters in the oil-rich Caspian Sea nation of Azerbaijan cast ballots Sunday in a parliamentary election that is expected to secure the ruling party's dominance.

BAKU, Azerbaijan — Voters in the oil-rich Caspian Sea nation of Azerbaijan cast ballots Sunday in a parliamentary election that is expected to secure the ruling party's dominance.

International rights groups have accused Azerbaijani authorities of limiting free speech, and the main trans-Atlantic security and rights group, the Organization for Security and Cooperation in Europe, has refused to monitor the vote after Azerbaijan demanded that it sharply cut the number of observers. It marks the first time since Azerbaijan won independence after the 1991 Soviet collapse that the OSCE will not monitor its election.

Azerbaijani President Ilham Aliyev's government long has faced criticism in the West for showing little tolerance for dissent and holding elections that fall below democratic standards.

Aliyev on Sunday strongly criticized the OSCE for refusing to monitor the balloting, saying its action violated the organization's ground rules, according a statement issued by the presidential office.

At the same time, Aliyev, in office since succeeding his father in 2003, has firmly allied the Shia Muslim nation with the West, helping secure its energy and security interests and offset Russia's influence in the strategic Caspian region.

The parliamentary race features 767 candidates competing for seats in the 125-member parliament.

Opinion surveys have indicated a strong lead for the ruling Yeni Azerbaijan party, the results reflecting a rise of incomes in the nation of 9 million under Aliyev's watch, thanks mainly to the country's oil wealth.

When the polling stations closed at 7 p.m. local time (1500 GMT), more than 55 percent of Azerbaijan's eligible voters had cast ballots.

Some leading opposition groups boycotted the vote. Ali Kerimli, the leader of Azerbaijan's Popular Front, said his party decided to stay aside because "the country lacks a proper political environment and legal base for conducting a democratic vote."

The leading opposition party, Musavat, also said just four days before the vote it was pulling out.

"We have demanded that the authorities create democratic conditions and equal opportunities for all political forces" and postpone the vote, said its leader, Arif Hajili.

Hajili said only 24 of the 73 candidates nominated by the opposition party have been registered for the vote by the authorities.

Election authorities, however, refused to take Musavat off the ballot, saying it's too late to do so, and accused the party of trying to thwart the vote. Some Musavat candidates reportedly have said they would stay on the ballot despite the party leadership's decision.

Amnesty International has protested what it described as "sustained and severe attack" on the freedom of expression in Azerbaijan in the run-up to the parliamentary election. It said there are at least 20 prisoners of conscience in Azerbaijan who have been convicted on trumped-up charges ranging from fraud to treason.

Amnesty said most of the country's independent human rights organizations have been shut down and prominent rights leaders arrested or forced into exile. It said an official crackdown has made activists fearful about criticizing human rights violations, while independent media is now almost non-existent and state-controlled media are used to smear critics.

Azerbaijani authorities have dismissed such criticism as unfounded.

Central Election Commission chief Mazahir Panahov said his agency hasn't observed any significant flaws during Sunday's ballot.