LUANDA, April 4 -- Over 1,000 Chinese expatriates on Monday held a memorial in Luanda to mourn the deaths of four Chinese nationals murdered in southern Luanda, Angola's capital in January over a failed land deal with local people .

Addressing the event organized by the General Chinese Chamber of Commerce in Angola, Chinese Ambassador Cui Aimin said the barbarous killings of the four Chinese citizens aroused wide-spread indignation and condemnation of Chinese nationals working in the African country.

Cui said the embassy had demanded prompt police investigations into the case and the suspects be brought to justice as soon as possible.

At the ceremony, Chairman of the General Chinese Chamber of Commerce in Angola Xu Ning read out an open letter to the Angolan government, which condemned the murder of the four Chinese nationals as inhuman and the most brutal crimes against Chinese citizens working in Angola in recent years.

The open letter demanded a prompt and thorough police investigation into the killings of the four Chinese citizens and appealed to the Angolan government for tougher measures to safeguard the interests of Chinese citizens in the African country.

The four Chinese citizens lost contact with their family and were reported missing on January 17 after they were invited to attend a meeting with a local land owner in Southern Luanda, with their bodies to be found on March 18 in a deserted water tank.

Police investigations showed the four Chinese were killed when they were trying to get back a down payment of 36 million kwanzas (about 210,000 U.S.dollars) over a failed land deal with local people.

Twelve Angolan suspects were rounded up by police, and seven of them were charged with directly involved in the murder of the Chinese citizens, including three soldiers in active service and a member of the Angolan special police.