Five Kuwaitis including an MP were treated in hospital for injuries on Wednesday as special forces cracked down on an unauthorised opposition rally, medics and witnesses said.
The elite special forces used batons to beat up dozens of participants, who included at least six opposition MPs, at the outdoor rally in Sulaibkhat, 10 kilometres (six miles) west of Kuwait City, witnesses said.
Medical sources said Islamist MP Waleed al-Tabtabai and four men were taken to hospital for treatment of wounds and fractures caused by the beating.
The rally was the second of a series of opposition protests against an alleged "government plot" to amend the 1962 constitution which made Kuwait the first Arab state in the Gulf to embrace parliamentary democracy.
After the police crackdown, 11 opposition lawmakers held an urgent meeting and decided to motion for the questioning of Prime Minister Sheikh Nasser Mohammed Al-Ahmad Al-Sabah, a senior member of the Al-Sabah ruling family.
Earlier in the day, the government of the oil-rich emirate warned it would not allow outdoor public gatherings and advised the opposition to organise their rallies indoors.
Kuwait, OPEC's fifth largest producer, has a 50-member parliament. The 16 cabinet ministers, of whom 15 are unelected, automatically become members of parliament and have similar voting rights as elected MPs.
The emirate has been rocked by a series of political crises over the past five years that led the ruler to dissolve parliament three times, while the cabinet has resigned five times.