The group conducted several assassinations of U.S. military personnel and civilians working in Iran during the 1970s. Between 1973 and 1975, the Marxist–Leninist MEK increased their armed operations in Iran. In 1973, they engaged in two street battles with Tehran police and bombed ten buildings including Plan Organization, Pan-American Airlines, Shell Oil Company, Hotel International, Radio City Cinema, and an export company owned by a Baha’i businessman. In February 1974, they attacked a police station in Isfahan and in April, they bombed a reception hall, Oman Bank, gates of the British embassy, and offices of Pan-American Oil company in protest of the Sultan of Oman's state visit. A communiqué by the organization declared that their actions had been to show solidarity with the people of Dhofar. On 19 April 1974, they attempted to bomb the SAVAK centre at Tehran University. On 25 May, they set off bombs at three multinational corporations.