The defendants railed against the presiding judge, Ottmar Breidling, in the western city of Duesseldorf on Wednesday as he handed down the sentences of between five and eight years in prison.
The defendants were accused of planning to set off a bomb near the headquarters of the Jewish community in Berlin and of plotting hand grenade attacks against a pool hall and a nightclub in Duesseldorf owned and frequented by Jews.
Aktham Sulaiman, Aljazeera's correspondent in Germany, said the trial started after the September 11 attacks and lasted for over three years.
The defendants did not confess they intended to attack the places in question. However, the prosecutors proved with evidence that these were possible targets of the group, the correspondent said.
Jordanians Muhammad Abu Dhiss and Ismail Shalabi and another Jordanian of Palestinian origin, Ashraf Muhammad Al-Dagma, were found guilty of belonging to a Muslim group which planned attacks on two Jewish-owned Duesseldorf discos and a Berlin community centre.
Algerian Djamil Mustafa had been charged with supporting the group and breaking Germany's weapons laws. Abu Dhisss received an eight-year sentence, Al-Dagma seven years and Shalabi six years.
The Algerian, who was found guilty of supporting the hardline group, was sentenced to five years in prison.
The prosecution described the defendants, aged between 32 and 41, as the "most important members" of the German cell of the Muslim group al-Tawhid whose overall commander is said to be the Jordanian-born al-Zarqawi.
The four defendants were detained in April 2002 after police carried out a phone-tapping operation, and went on trial in February last year.