In June 1981, street battles broke out between the Revolutionary Guard and the left-wing Mujaheddin e-Khalq (MEK), continuing for several days and killing hundreds on both sides. In September, more unrest broke out on the streets of Iran as the MEK attempted to seize power. Thousands of left-wing Iranians (many of whom were not associated with the MEK) were shot and hanged by the government. The MEK began an assassination campaign that killed hundreds of regime officials by the fall of 1981. On 28 June 1981, they assassinated the secretary-general of the Islamic Republican Party, Mohammad Beheshti and on 30 August, killed Iran's president, Mohammad-Ali Rajai. The government responded with mass executions of suspected MEK members, a practice that lasted until 1985.