BANDA ACEH, Aceh: One minute's silence was observed Monday to mark the exact moment a year ago that the devastating Indian Ocean tsunami smashed ashore in Indonesia's Aceh province. "Ladies and gentlemen, let us now bow our heads in silence to pray for the souls of hundreds of thousands who lost their lives as a result of the tsunami of Dec. 26 last year," President Susilo Bambang Yudhoyono said.

"May they rest in peace by God's sight. The moment of silence begins," he said at a ceremony at the Ulee Lheu mosque on the outskirts of Banda Aceh, an area totally destroyed except for its mosque.

The president turned on a wailing siren, which activated an early warning system that is in the process of being set up to prevent a repeat of the tragedy that saw some 220,000 lives taken from Indian Ocean nations.

Of that toll, 168,000 were Indonesians and most died in the westernmost province of Aceh.

Susilo listed the numbers of dead and missing across the 12 countries where people died when the waves crashed ashore after they were unleashed by one of the world's largest ever recorded earthquakes.

"We stand here together today in remembrance of that suffering, paying respect once again to the good men and women and all the children lost to the sea," he told the gathered crowd of about 500, including representatives from dozens of foreign countries.

"We bow our heads in deep prayers so that the souls of the loved ones, found or not found, at land or at sea, have a proper resting place at God's side... We are here to also honor those who survived.

"These sons and daughters, brothers and sisters, parents, they all want to regain their lives."

At Banda Aceh's Baiturrahman Grand Mosque, hundreds of white-clad Acehnese gathered simultaneously and held a mass prayer led by top preacher Muhammad Arifin Ilham.