Iraqi police say a senior provincial official has been assassinated in the central town of Baquba.

Police say unidentified gunman shot dead Aqil Hamed al-Adeli, a high raking official in Iraq's Diyala province, Friday.

Few details have emerged about the incident.

Farther north, in the town of Tikrit, Iraqi officials say they doubt that a bullet-riddled body of an Asian-looking man is that of a Japanese hostage, a 24-year-old man, Shosei Koda, who was kidnapped by militants demanding that Tokyo withdraw all its troops from Iraq.

An execution deadline set by the young man's captors has expired, but Japanese officials say they are making efforts to secure his release. Japan has more than 500 non-combat troops in Iraq, working on reconstruction and humanitarian projects south of Baghdad.

In another development, Iraq's interim government is urging residents in the central town of Fallujah to expel terrorists and avoid an all-out assault on their city, which is at the center of the insurgency in Iraq.

Interim Prime Minister Iyad Allawi has appealed to the people of Fallujah to seize what he calls their last chance for a peaceful resolution, by throwing out militants linked to Abu Musab al-Zarqawi. The Jordanian-born militant is believed to be hiding in Fallujah.