A candlelit memorial service was planned for sunset at Patong beach on Thailand's resort island of Phuket on Wednesday.

The event was held to commemorate the eigth anniversary of the Dec 26, 2004 tsunami.

Music, speeches, prayers and a minute of silence were scheduled to be observed by survivors and mourners.

The Boxing Day tsunami claimed about 8,000 people in Thailand's southern provinces, about half of them foreign tourists.

The National Disaster Warning Centre has since set up warning towers and tsunami-detection buoys in the Andaman Sea to respond quickly to any earthquake and subsequent tsunami.

In Indonesia, Mutmainah sat quietly with her brother on Wednesday at a mass grave in Siron, on the outskirts of Banda Aceh on Sumatra Island, quietly reading their prayer books.

They lost five members of their family in the tsunami that killed nearly a quarter of a million people.

"We left Aceh after the tsunami, we didn't reopen our shop in Banda Aceh and moved it to Medan," she explained at the commemoration of the eighth anniversary.

The middle-aged siblings joined hundreds of others in mourning at mass graves and local mosques.

Music and prayers were performed throughout the day at a newly built tsunami museum in the hardest-hit region of Aceh.

The disaster triggered by a magnitude-9.3 earthquake off Sumatra killed an estimated 230,000 people in 13 countries along the Indian Ocean, including 170,000 in Aceh and Nias island.

Thousands attended a ceremony to mark the anniversary in Malahayati port in Krueng Raya, outside the provincial capital, attended by Aceh Governor Zaini Abdullah.

Red-and-white Indonesian flags flew at half-mast along the streets leading to the port.