The first election results are expected late Saturday in Bahrain, where voters cast ballots earlier in the day for the 40-seat parliament.
The election comes at a time when tensions have mounted between the Sunni Muslim-led government and the country's Shi'ite majority.
A string of opposition arrests has prompted fears that the monarchy is beginning to abandon its attempts at democracy and return to authoritarianism.
At least 250 Shi'ite activists have been detained in the last two months, and 23 Shi'ites accused of plotting to overthrow the government are scheduled to go on trial next week.
Shi'ites also say they are denied equal housing, health and education benefits and that most government institutions refuse to hire them.
Shi'ites make up more than 70 percent of Bahrain's population. Some representatives of the group accused Sunni leaders of issuing Bahraini passports to foreign Sunnis who did not meet naturalization requirements in order to weaken the Shi'ite majority. The government denied the charge.
A government election official (Abdullah al-Buainain) said 300 or more observers monitored the elections to make sure they are fair.
News organizations say the final results are due to be announced Sunday in what is only the third election in Bahrain under its eight-year-old constitution.
The United States has a key interest in the vote. Pro-Western Bahrain hosts the U.S. Navy's 5th Fleet, which patrols the Persian Gulf at a time when Western concerns about Iran's nuclear development program have risen sharply.
Some information for this report was provided by AP, AFP and Reuters.