Friday's incident was the second time in a month that tribal members clashed with police over primaries that became illegal in 1998 in the Gulf country.
Kuwaiti tribes are holding the secret primaries to pick their candidates for parliamentary elections on May 17.
Kuwait has criminalised the vote because authorities believed it encourages allegiance to the tribe rather than the state.
It also deprives many Kuwaitis from a fair chance to compete in the same district if they are not supported by a tribe.
Police have arrested scores of Kuwaitis for holding the banned vote so far.
But the tribes have been finding a way of to getting around the crackdown by calling for "consultations" of tribesmen or organising the vote under the guise of dinner banquets.
There have also been reports that the internet was used for the polling.
Diwaniyas, which have always existed in Gulf culture, are part of the social and political fabric of Kuwait.
They are used by men and, more rarely, by women, often simply to meet socially in the evenings.
The Kuwaiti government has said it will demolish 30,000 diwaniyas built illegally on state-owned land - including those belonging to members of parliament, former ministers and wealthy citizens.
Kuwait's parliamentary elections were scheduled after the emir, Sheikh Sabah al-Ahmed Al-Sabah, disbanded the parliament last month because of tensions between the legislature and the cabinet that prompted the resignation of several ministers.