Japan and Japanese nationals overseas could still be the targets of terrorism as the al-Qaida terrorist network continues to condemn nations that supported the use of force against Iraq in 2003 and to call for "jihad," or holy war, the National Police Agency said Tuesday in an annual report on security.

"There are many facilities (in Japan) linked to the United States, and we cannot rule out the possibility that Japan could be a target of terrorism," the agency said in the report analyzing the prospect of international terrorism over the next year.

The report says Islamic groups in various parts of the world that have no relations with the leadership of al-Qaida could be influenced by the group and engage in terrorism.

Japan supported the United States and its allies in the war against former President Saddam Hussein's Iraq in March 2003.

Noting that young British Muslims were involved in multiple bomb attacks on London's underground rail network and buses last July, the agency indicated it is necessary to keep an eye on Muslim communities in Japan.

"There are concerns that Islamic extremists may use such communities (in Japan) to raise funds or encourage young people in the communities to become radical," the report says.

Also mentioned in the report is an incident in Iraq in May in which a Japanese security worker was killed by an Iraqi militant group. "There is a concern that overseas Japanese nationals or Japanese interests could be a target of terrorism," it says.

Security worker Akihiko Saito was traveling in a convoy when it was ambushed by the militants. Saito died after being taken hostage by the group.