More than 500 people gathered at a Singapore mosque last night to bid farewell to the Iranian twin sisters who died on Tuesday shortly after surgeons had separated them.

For the simple 45-minute prayers service attended by various faiths Ladan and Laleh Bijani lay in separate coffins, the first time they had not been together in public since they were born 29 years ago in southern Iran.

Sealed in preparation for this morning's repatriation to Iran, the coffins were covered in black sheets inscribed with Koranic verses. A bunch of white daisies and green ferns lay on each one.

Many grander floral tributes from groups as diverse as a dance troupe, the land transportation authority, a gift shop and restaurants lay outside the Ba'alwi mosque.

Many were addressed to "Our beloved Ladan and Laleh", a testament to how Singapore had embraced the sisters since they arrived six months ago.

A nun, Sister Colette, said at the memorial service: "We all had followed every move they had made while here. I was so impressed both by them and the affection people had for them."

Like many mourners, she felt it was "a blessing in disguise" that both sisters had died. "If one had lived, she would have felt continuous guilt."

A member of the Iranian community, Mohammad Zafar, said the twins would now be happy. "At least they are now separate but still together," he said. "They have achieved their goal."

After the prayers Iranians read out scores of messages of condolences from all over the world.

Doctors in Singapore and elsewhere had discouraged the sisters from having the operation, which had never been performed on adults. But the sisters, law graduates who wanted to pursue independent careers, refused to be dissuaded, even though the chance of success was considered small.

Surgery began on Sunday morning and the separation was completed 51 hours later. But within 45 minutes Ladan died from massive blood loss. Laleh died 90 minutes later, also because of circulation failure. Neither had regained consciousness.

Their bodies were taken to an Islamic school used by the small Iranian community yesterday and were washed in accordance with Islamic tradition.

After an hour of prayers they were taken to to the mosque.

Their bodies are due to be flown home to Iran this morning.