Clashes with authorities came a day after protesters burned down the tent after offensive comments were made [AFP]

More than 20 people were wounded when Kuwaiti riot police clashed with tribesmen who stormed a local television station in a second day of violence before parliamentary elections, witnesses said.

The incident took place late on Tuesday at the offices of the privately-owned Al-Watan satellite channel which was hosting Nabeel al-Fadl, a pro-government candidate in Thursday's vote to determine Kuwait's 50-seat parliament.

Police used tear gas to disperse the crowd that started throwing stones, wounding around 20 security men and four reporters, a witness told AFP.

Some of the angry crowd managed to enter the offices and damaged some furniture and equipment, but all staff members escaped unhurt. They later attacked a nearby fire station, the witness added.

Around 15 tribesmen were arrested during the clashes.

The incident came a day after angry tribesmen burned down the election tent of Mohammed al-Juwaihel, a controversial pro-government candidate and ally of Fadl, over remarks deemed offensive to the Mutairi tribe, the second largest Bedouin clan in Kuwait.

Al-Juwaihel has alleged that many tribes are not "true Kuwaitis" because of ancestral roots in Saudi Arabia that allow them to obtain dual citizenship and gain access to generous welfare systems in both countries.

Opposition tribal candidates held a massive rally to condemn Juwaihel's remarks and to ask the government to take legal action against him.

"We tell the (ruling) family that we are partners in governance and public funds and we are free people," Mussallam al-Barrak, a leading opposition candidate, told a crowd of over 20,000 who listened to him under heavy rain.

Kuwait's royal court, many election candidates and a large number of political groups on Tuesday strongly criticised the Juwaihel incident as well as the tribesmen's response.

The royal court warned in a statement that the incident risked "fuelling divisions in society," and called on Kuwaitis to steer clear of anything that could negatively affect the elections.

Veteran opposition figure Ahmad al-Saadun charged that anti-democracy elements were trying to discredit elections in which the opposition is tipped to win.

"This time we are before an abnormal struggle ... Parties that will not come back (to parliament) will not remain silent ... They want to sabotage the election," Saadun told an election rally on Tuesday night.

The liberal National Democratic Alliance described Juwaihel and his associates as "puppets and destructive tools being moved by certain quarters in the regime."

Oil-rich Kuwait has been hit by a series of political crises over the past six years leading to the resignation of seven governments and the dissolving of parliament on four occasions.