Bahrainis voted for a new parliament on Saturday at a time of rising sectarian tension in the small Gulf Arab kingdom, where decision-making is tightly controlled by its rulers.

Bahrain, home to the US Fifth Fleet, has a Shia Muslim majority population but is governed by the Sunni Al Khalifa dynasty, which allies Saudi Arabia and the United States see as a bulwark against the regional influence of Shia power Iran.

The opposition said 1,000 voters in Shia districts were turned away from polling booths after being told their names were not on the register. The government denied the charge.

"The opposition claims their followers are being targeted and that these were people who have been active in their campaign," Abdulnabi Alekry of the independent poll monitor the Bahrain Transparency Society told a news conference.

He said the complaints came mostly from the northern and central governorates, areas with mostly Shia populations.

But Foreign Minister Sheikh Khalid bin Ahmed Al Khalifa told a news conference voting lists had been published in August.

"It shows and proves that this democratic process is continuing, it's solid, it's strong," he said.

Saturday's election was the third since the creation of the current parliament, which has limited powers since bills need to pass an upper house whose members are appointed by the king.

Bahrain, with 1.3 million inhabitants and no oil and gas reserves, relies on foreign investment and tries to present itself as having a business-friendly environment.

Many Bahraini Shias say they face discrimination over state housing and jobs, a charge the government denies.

The run-up to the vote was overshadowed by a broad security crackdown against some Shia opposition groups in August that also targeted bloggers and human rights activists. Next week, 23 men charged with plotting to overthrow the political system will appear in court for the first hearing in their trial.

Observers said the level of participation and any increase in street protests after the elections would be more telling than the actual results, where few changes were expected.

Some districts where candidates fail to win 50 percent of the vote could see a second round of polling next Sunday.

The island kingdom is the smallest Gulf Arab nation. But a reform process begun by King Hamad bin Isa Al Khalifa a decade ago has been closely watched in the region, especially after the 2003 US invasion of Iraq brought Shias to power there.

Abdallah Hassan from the Shia village of Karranah said he did not think the vote would help address his community's grievances. "There is no change in Bahrain, whether you have elections or not ... The parliamentarians can't change the laws and the economic situation".

Another Shia voter was more optimistic. "A new parliament takes time to work well. After the elections in 2014, 2018 we will see some results," said Umm S Ali in the village of Kazarkan.

The polls opened at 0500 GMT and were to close at 1700 GMT. Results were expected to be announced on Sunday morning.

Critics accuse Bahrain of apportioning its voting districts in such a way as to ensure the Shia opposition will not have a majority in parliament.