Thousands of protesters briefly cut off the sixth ring road, the main motorway in the south of Kuwait City on Sunday following a last minute change of venue. Riot police responded with stun grenades and smoke bombs to disperse the crowd.

Dozens of people were arrested, activists said, although there were no reports of any injuries.

Organizers called the protest off an hour after it began, declaring it a success. "After we have expressed our message of rejecting any play in the constitution, we announce the end of the procession," said the organizers on their Twitter account named "The Dignity of a Nation."

Tensions mounting

Although Kuwait has so far avoided the mass pro-democracy unrest that has ousted rulers in four other Arab nations since last year, tension has mounted in the last few months. Since October 21, the nation has seen three major protests as it suffers a long-running power struggle between parliament and the government which is dominated by the ruling Al-Sabah family.

The latest protest came in response to a disputed amendment to the electoral constituency law ordered by Emir Sheikh Sabah al-Ahmad al-Sabah last month ahead of a snap December 1 parliamentary election. Some opposition politicians have argued the changes are an attempt to give pro-government candidates an advantage in the polls.

Next month's elections are the second in Kuwait this year. In February an opposition bloc of Islamists, liberals and tribal leaders won a majority in the polls, but the constitutional court quashed the vote in June and reinstated the previous pro-government parliament which was dissolved last month.

Almost all opposition groups have said they will boycott the elections and have called for further demonstrations.

ccp/mr (AFP, Reuters)