Indonesia has marked four years since the Indian Ocean tsunami with prayers and remembrance of one of the world's worst ever natural disasters.
Indonesia was the nation hardest hit by the tsunami. At least 168,000 people killed when water smashed into Nias Island and Aceh province, which sits on the northern end of Sumatra.
Thousands of Acehnese gathered among the shattered remains of a military base in the coastal town of Meulaboh, one of the areas worst-hit by the earthquake-triggered tsunami.
Around 50 tsunami survivors, left homeless after the disaster, chanted and waved placards after the ceremony demanding housing and accusing authorities of failing to look after victims.
Prayers were also held in mosques throughout the staunchly Islamic province, including tearful ceremonies at mass graves in the tsunami-devastated capital of Banda Aceh.
Indonesia also held tsunami drills at the northern end of the sprawling island of Sulawesi, including one in Manado city attended by President Susilo Bambang Yudhoyono.
The 2004 disaster, which killed more than 220,000 people in total, including in Sri Lanka, Thailand and India, led to an outpouring of international aid.
Some $7.2bn was pledged to Aceh and Nias in the month after the tsunami, according the official reconstruction agency.
The agency says reconstruction in affected areas is nearly complete, with $6.7bn in aid money spent and nearly 125,000 homes built as well as schools, roads and bridges.
However, around 1,000 tsunami victims still live in barracks and there are concerns of a rise in economic misery as the aid boom that has driven the local economy dries up.
