Singapore is investigating how 121 of 1,704 sheep imported from Ireland for the Aidiladha ritual slaughter were found dead upon arrival here.

"We are investigating how this happened," Prime Minister Lee Hsien Loong said today in a Facebook post where he wished Singapore Muslims "Selamat Hari Raya Haji".

"Muslims also perform the 'korban' (sacrificial) rites today and distribute the meat to the less fortunate and share among families and friends. Unfortunately, some sheep did not survive the flight to Singapore," he wrote.

It was reported Sunday that more than 3,500 sheep arrived in Singapore from Australia and Ireland ahead of the ritual slaughter at 26 mosques to mark Aidiladha.

A total of 1,867 sheep from Australia arrived on Friday and were transported to 13 'korban' centres.

However, out of the 1,704 sheep imported from Ireland on Saturday, 121 were found dead on arrival.

The Singapore Mosques Korban Committee reportedly said that post-mortem findings indicated that heat stress was the cause of death.

"Nevertheless, the korban rites are carrying on as scheduled. Those who have pledged to do korban are able to do so. My deep appreciation to all who have worked hard to enable korban rites to take place here," Lee wrote further.

In his post, Lee was also wished Singaporean pilgrims "a safe and meaningful journey".

"This year, 680 of our pilgrims have made the journey to fulfill their Hajj. The hajj is the fifth pillar of Islam.

Every year, millions of Muslims perform this pilgrimage to the holy land in Saudi Arabia," he wrote. -- BERNAMA