Responsibility
Islamic Jihad Organization and Islamic Dawa Party were reported at the time to be involved in the bombing. Shortly after the blasts, Islamic Jihad called Kuwaiti authorities to take responsibility for the blast. This claim and was taken seriously after the callers boast that there was a "seventh bomb" was verified by the discovery of a car bomb in front of the Immigration Bureau.
More important than Islamic Jihad was Islamic Dawa. It was connected to the bombing when the remains of a human thumb were found and its thumbprint identified as that of Raad Murtin Ajeel, a 25-year-old Iraqi Shia member of Dawa. Ultimately 21 other defendants were put on trial (17 captured in a nationwide manhunt and four tried in absentia). After a six-week trial, six were sentenced to death (three of those were in absentia), seven to life imprisonment, seven to terms between five and fifteen years. (One of those convicted was Jamal Jafaar Mohammed, currently member of Iraq's parliament and member of Prime Minister Nuri al-Maliki's ruling coalition, and accused of acting as an Iranian agent in Iraq.)
Read more about this topic: 1983 Kuwait Bombings