The Italian police arrested an Iraqi man with extremist ties on Monday who they suspect helped foreigners pass illegally through the southeastern port city of Bari. The police identified the man as Majid Muhamad, 45, who served 10 years in an Italian prison on terrorism charges, and who was released a year ago. “He was a known terrorist” who had been affiliated with Ansar al-Islam, a radical group often linked to Al Qaeda, said Michele De Tullio, an official with the police’s special operations division in Bari. The investigation began in February, when Mr. Muhamad was found to be in contact with Ayachi Bassam, an imam in the Brussels district of Molenbeek, who was arrested — and later convicted — on terrorism charges in Bari. Mr. Bassam was released on appeal. Mr. De Tullio said that since Mr. Muhamad’s release, he had “renewed his contacts to extremist affiliates.”