APIA, Samoa - Tears flowed as wreaths were laid for each of the 143 casualties of Samoa's tsunami at a mournful memorial service here Thursday.

As the names of the South Pacific islanders who died were read out, children laid white wreaths by the front of a stage where the coffins of 11 of the victims were placed.

Relatives and many other mourners wept as the names were announced at the emotionally-charged service attended by more than 2,000 people at Apia Stadium.

The foreign holidaymakers killed in the tsunami on Tuesday last week were also remembered with purple wreaths.

Iuma Tafua lost 13 relatives and said the memorial service helped his family cope with their loss.

"I am comforted in the knowledge that our nation cares and has come together to mourn the loss of those dear to me and my family," he told AFP.

"This ceremony will assist in the grieving process."

Originally at least 100 victims of last week's tsunami were expected to be buried together in the Apia cemetery.

But most families instead elected to bury their loved ones the traditional way in family plots near their homes - or where their homes used to stand.

The 11 coffins were earlier brought into the stadium on three police trucks covered with ceremonial woven cloths known as tapa as a police band played funeral hymns.

Prime Minister Tuila'epa Sailele Malielegaoi told the mourners that Samoans' innate resilience would see them through the tragedy, as it had in previous disasters.

"Our people are used to tragedy and sadness. We are generally prepared and the end of this tragedy will signify the beginning of preparations for the next tragedy."

The victims would never be forgotten, he said.

"Although no longer amongst us, they shall remain an indelible part of our collective memory and of the history of our nation."

Flags flew at half mast all day in Apia and the mood was sombre ahead of the memorial service.

As well as the national day of mourning, a half day's holiday was declared for Thursday, with businesses and government offices closing at midday.

After the memorial service, the 11 caskets were taken in a solemn procession to a new cemetery nearby as bystanders threw flowers on to the caskets.

In a simple ceremony of prayer and songs, police laid the 11 victims side by side in marble-lined graves as the sun set over the capital.

The hillside cemetery overlooking the ocean will be surrounded by a garden and a permanent memorial built to commemorate all the victims of the devastating event.

Six people remain missing in Samoa and thousands are homeless after the tsunami, triggered by an 8.0 magnitude earthquake, smashed into the southern coast of the most populated island of Upolu.

Another 32 people were confirmed dead in neighbouring American Samoa and nine on Tonga's northern island of Niuatoputapu.

Samoans relived last week's terror on Wednesday when a 7.8 earthquake near Vanuatu - followed in quick succession by two more tremors over 7.0 - sparked a Pacific-wide tsunami alert.

Panicking residents caused traffic gridlock in the capital Apia and homeless survivors from last week's devastation fled their makeshift hill camps to run higher up the slopes.

A second tsunami was not generated but the alert inflamed emotions still raw from a week earlier.