A 47-year-old Pakistani American ice cream truck driver and his son have been arrested by the Federal Bureau of Investigation (FBI) for their possible connections with the Al Qaeda terror network, The New York Times reported.

Umer Hayat and his 22-year-old son Hamid Hayat were arrested and were being held at a jail in Sacramento, California.

The FBI affidavit filed in a federal court said the junior Hayat was allegedly trained at an Al Qaeda camp in Pakistan where he target practised on the photographs of top US leaders, including President George W. Bush.

The paper said Hamid Hayat, who was born in California, returned to the US on May 29 after spending more than two years in Pakistan. He began working last week as a cherry picker with a local fruit packing company.

Johnny L. Griffin III, a lawyer for the father, was quoted as saying: "They are not charged in this complaint with committing any terrorist acts, and they are not charged in this complaint with supporting any terrorist acts."

Two other men, both imams at two Pakistani mosques, were detained in connection with the investigation. The authorities said the two imams, who are not American citizens, were being detained for immigration violations. A lawyer for the two imams said his clients were innocent of any wrongdoing.