A bomb exploded in Jakarta's international airport early Sunday, wounding 11 people, one seriously, police said.

The blast occurred at about 6:30 a.m. behind a Kentucky Fried Chicken restaurant in the departure area of the domestic terminal, said Jakarta (search) police spokesman Prasetyo, who uses a single name like many Indonesians.

Police Chief Gen. Da'i Bachtiar said the explosion was due to a bomb, adding there was no immediate claim of responsibility.

Dede, a food service worker in the airport, said by telephone that there was a brief power outage, "then I heard a loud explosion."

He and other witnesses said the blast knocked out windows and tossed chairs across the terminal. There was blood everywhere, they said.

Police had sealed off the area near the restaurant but the terminal was open and flights were departing, Dede said.

The blast comes four days after Abu Bakar Bashir (search) -- the spiritual leader of the Al Qaeda-linked terror group Jemaah Islamiyah (search) -- went on trial for treason. It also follows the arrest Wednesday of 18 members of the group, including three wanted in the Oct. 12, 2002 Bali bombings which killed 202 people.

On Thursday, a small pipe bomb exploded outside the main U.N. building in downtown Jakarta but no one was injured.