The assailant hit Zaid on the face with a metal object while he was sitting in his car immediately after giving a lecture about corruption in the oil-rich Gulf state late on Sunday, according to Alaan.
He was rushed to hospital where he underwent minor surgery.
Lawmakers condemned the assault, saying it happened because of Zaid’s fight against corruption, and urged the government to apprehend the assailants.
Prime Minister Sheikh Nasser Mohammad al-Ahmad al-Sabah also condemned the attack and promised to arrest the perpetrators.
In recent years, Zaid has written many articles and delivered lectures about what he sees as widespread corruption practices in the emirate, which sits on around 10 percent of global proven oil reserves.
Kuwait has been downgraded on the Berlin-based Transparency International corruption perceptions index in each of the past six years. Last year it had slipped to 65th place from 35th in 2003 among 180 countries monitored.
