Most people do not know that the names of  Al-Qaeda and Mujahedin-Khalq (known as MEK, NRI, and many other front names) are driven from the same verse (Surah:Al-Nesa, verse 95, Quran). The last part of the verse reads:

فضل الله المجاهدين على القاعدين اجرا عظيما

(Translation: Not equal are the believers who have no impediment who stay [at home] and al-mujahiduna (those who do jihad) in the way of Allah with their properties and selves. Allah has favored al-mujahidina (those who do jihad) with their properties and selves above those who stay [at home] with a higher degree; and Allah has promised good to both. And Allah has favored al-mujahidina (those who do jihad) above those who stay [at home] with a mighty reward )

The MEK uses the last section of the verse for its organizational emblem: Also both groups use 19th and 20th century totalitarian ideologies of Marxism and Fascism in their literature to justify their actions and goals. 
 
A common practice among both groups is suicide bombings, but Mujahedeen were certainly pioneers in using suicide attack against the clerical leaders of Iran. Some may assume that suicide bombings started in Beirut when on October 23, 1983 the U.S. Marine Corps headquarters and the French army barracks were attacked. But the fact is that the MEK started suicide bombings in 1981 against the ruling mullahs in Iran, after they wereforced out of the political arena. On September 1981, Ayatollah Madani, the Friday prayer leader of Tabriz, was the victim of a suicide bomber named Majid Nikoo, a member of the MEK. A month later Ayatollah Hashemi-Nejad was killed in another suicide mission claimed by the MEK. In December of the same year, another member of the MEK named Gohar Adab-Avaz killed Ayatollah Dastgheib in a suicide attack in Shiraz and was praised by MEK as a “Great Mujahed.” The MEK called these attacks “عمل فدایی حسینی” (Imam Hussein sacrificial operation) and “عملیات انتحاری مقدس” (sacred suicide operations).
 
This is not by any means a full list of suicide missions by the MEK in Iran. Such tactics in early 1980s, gave mullahs a perfect excuse to further brutalize the MEK, and the rest of the opposition groups..