Security is tight as Islamic militant Umar Patek arrives at court in the Indonesian capital Jakarta.

Forty-five-year-old Patek is accused of making bombs for the 2002 Bali nightclubs attack that killed 202 people.

He is also accused of mixing the chemicals for 13 bombs that detonated at five churches in Jakarta on Christmas Eve 2000, claiming 15 lives.

After being sworn in, a witness at one of the churches describes what happened.

(SOUNDBITE) (Bahasa Indonesia) WITNESS WHO WAS IDENTIFIED AS WAGIONO SAYING:

"We were on our way to the gate of the church, heard the explosion and then saw there was a fire, and I thought, I need to extinguish the fire."

A policeman testified that one of the bombs was located outside the parking lot, near the burning car.

Patek's lawyers - who had previously asked for the charges to be dropped on the grounds that they were "insufficient" - say the case against their client is weak.

(SOUNDBITE) (Bahasa Indonesia) UMAR PATEK'S LAWYER ASLUDIN, SAYING:

"The witnesses so far are not touching on his involvement as a defendant in this case."

Patek was caught in Abbottabad by Pakistani authorities in January 2011, the same town where U.S. forces later shot dead Osama bin Laden.

Nick Rowlands, Reuters.