A Kuwaiti court on Thursday freed three Twitter users on bail after detaining them for nine days for allegedly insulting the ruler of the oil-rich Gulf state, a rights activist said.

A fourth tweeter however remained in detention as his case will be heard by a court on Sunday, the director of the Kuwait Society for Human Rights, Mohammad al-Humaidi, said on his Twitter account.

The Kuwaiti government on Thursday launched a media campaign to convince voters to cast their ballot in the December 1 poll in a bid to counter opposition calls for a boycott over a disputed law.

The campaign comes a day after Emir Sheikh Sabah al-Ahmed al-Sabah urged the public to be "positive" and cast their votes to elect the best candidates.

The Kuwaiti opposition has announced it will stage a major demonstration on the eve of the December 1 parliamentary election as a finale to its nationwide campaign to urge a boycott of the disputed polls.

The Islamist, nationalist and liberal opposition all say the poll boycott is in protest at the government's unilateral amendment of the electoral law, which it says breaches the constitution.

Kuwait on Saturday marked the golden jubilee of its constitution with a spectacular $15-million fireworks display which earned the wealthy Gulf state a place in the Guinness Book of World Records.

"I am happy to verify that with 77,282 fireworks, a new Guinness world record has been set tonight" in Kuwait City, a representative of Guinness World Records announced on Kuwait television at the end of the display.

Kuwait has released two members of the al-Sabah ruling family after holding them for two days allegedly over tweets deemed critical of the government, they said on Twitter Saturday.

Sheikh Abdullah Salem al-Sabah was released late on Friday, while Sheikh Nawaf Malek al-Sabah was freed on Saturday afternoon.

OPEC member Kuwait plans to spend some $100 billion on oil projects inside and outside the Gulf state over the next five years, a top oil executive said Monday.

"Around $100 billion has been earmarked for oil projects ... 60 percent of it on upstream projects inside and outside Kuwait," CEO of national oil conglomerate Kuwait Petroleum Corp. Faruq al-Zanki told reporters.

Kuwaiti riot police used stun grenades and smoke bombs against thousands of demonstrators who blocked a major road south of the capital on Sunday as the emir met four leading opposition figures.

After elite special forces and police completely sealed off the original protest site in Kuwait City, organizers told supporters via Twitter to gather instead at Mishref, some 20 kilometers (12 miles) south of the capital.

A Kuwaiti court on Thursday ordered the release on bail of opposition leader Mussallam al-Barrak following a night of violent protests that left dozens hurt, his lawyer said.

News of the court order came as opposition groups convened in an emergency meeting in the wake of the night-long clashes, which also saw more than 20 demonstrators arrested, according to activists.

A Kuwaiti opposition figure said he has been summoned for questioning after allegedly criticizing the emir on television, as the Gulf state widened a crackdown on dissent.

"I will go to the public prosecution (on Wednesday) for interrogation on the accusation of undermining the status of the emir in a televised interview in August," former Islamist MP Faisal al-Muslim said on Twitter.

The Kuwaiti opposition said on Monday it will push ahead with protests until the government meets its demands for reform, a day after 100 demonstrators were injured in confrontations with police.

"Despite the government's oppressive measures, we affirm that we will continue with the protest campaign... and we will announce new actions soon," the opposition said in a statement after holding an emergency meeting.