WASHINGTON – The FBI and Homeland Security have issued a nationwide warning about al-Qaida threats to small airplanes, just days before the anniversary of the 2001 terrorist attacks.

Authorities say there is no specific or credible terrorist threat for the 10-year anniversary of the attacks on the World Trade Center and Pentagon. But they have stepped up national security as a precaution.

According to a five-page law enforcement bulletin issued Friday, as recently as early this year, al-Qaida was considering ways to attack airplanes. The alert said terrorists have considered renting private planes and loading them with explosives.

“Al-Qaida and its affiliates have maintained an interest in obtaining aviation training, particularly on small aircraft, and in recruiting Western individuals for training in Europe or the United States, although we do not have current, credible information or intelligence of an imminent attack being planned,” according to the bulletin.

The bulletin also says al-Qaida would like to use sympathetic Westerners to get flight training, then get them to become flight instructors.