DUBAI (Reuters) - Bahrain will hold a second round of voting for 31 of 40 seats in parliament next week, the government said on Sunday, in an election from which opposition groups have been barred.

The authorities said voter turnout on Saturday was 67 percent, higher than a turnout of 53 percent in 2014 when opposition groups boycotted elections in the small Sunni Muslim-led, Western-allied kingdom.

Activists had called for a boycott of this vote, describing it as a “farce”, amid a crackdown on dissent by the ruling Al Khalifa family since the Shi’ite opposition staged a failed Arab Spring uprising in 2011.

Al-Wefaq, one of the main dissolved opposition groups, disputed the official turnout figure, saying in a statement that it had not exceeded 30 percent.

A run-off vote will be held on December 1, according to a statement carried on the Bahrain News Agency.

Only 23 of 40 current members ran for re-election. Two incumbents won their races, while another seven remain in the running to retain their seats in parliament, which has limited powers.

Bahrain has closed opposition groups, barred members from running in elections and prosecuted scores of people, many described by human rights groups as activists, in mass trials since 2011.

Minister of Justice, Islamic Affairs and Endowments Sheikh Khalid bin Ali Al Khalifa said Saturday’s turnout ensures a “clear mandate” for parliament.

“Bahrainis’ commitment to exercising their ballot was a clear indication of Bahrainis’ support for the process of democratization ... and showed their rejection of external forces who have deliberately sought to derail the electoral process,” he said in a statement late on Saturday.

Bahrain, home to the U.S. Navy’s Fifth Fleet, accuses Iran of fostering unrest that has seen demonstrators clash with security forces, who have been targeted by bomb attacks. Tehran denies the charges.