PORTLAND – Nearly six months after the deadly terror attacks, the question of why the accused mastermind began that fateful day on a commuter flight at the city’s small airport remains unanswered.

The FBI special agent in charge of the Boston field office has offered assurances that there is no substantial terrorist presence in Maine.

But law enforcement officials who have chased hundreds of leads still don’t know why Mohamed Atta and his companion Abdulaziz Alomari picked Portland as the starting point for the deadly attacks.

“The big question remains: Why did Atta and Alomari choose Portland?” said Portland Police Chief Michael Chitwood.

Atta and Alomari spent the night at a South Portland motel and flew from Portland before linking up with other hijackers and taking Boston flights that crashed into the World Trade Center.

Many Mainers are still unnerved by the thought of terrorists being in the state despite the FBI’s statements that there’s no evidence of terrorist cells. Unconfirmed sightings of Atta haven’t helped, either.

But Chitwood said there has been nothing documented to show that Atta or Alomari had any connection to Maine before Sept. 10. “There’s no indication of any prior interaction with anyone,” he said.