Two Singaporeans have been reported missing in Malaysia, with Malaysian authorities deploying a search and rescue operation to find them.

Bernama said in a report on Tuesday (Feb 6) that the man and woman were reported missing at 5.55pm on Monday.

They are believed to be missing at Gunung Pulai, a mountain in Malaysia's Kulai district in Johor.

Kulai District Police chief Superintendent Dzulkhairi Mokhtar said the search and rescue operation involved 28 personnel from the state Fire and Rescue Department, the police and the state Forestry department, Bernama reported.

The pair had not been found as of 11am on Tuesday.

On Facebook, friends have made posts saying that a woman named Clarice or Lum Jie has been uncontactable since Monday.

Chloe Quek Yixuan wrote: "We are very worried for her and grateful if you may help share this post or look out for her."

She added that Ms Lum was last seen in a green top and tights and had on a backpack and running shoes.

"She is in Johor Baru as per police records but we have no leads about who she is or was with," wrote Ms Quek.

Another person Aiping Chua wrote that Ms Lum "might have been in company with someone by the name of Dominick Tan".

The Straits Times contacted Ms Lum's relative but he declined comment.

A spokesman for the Ministry of Foreign Affairs told ST that the Singapore Consulate-General in Johor Baru is in contact with local authorities which are coordinating the search operations.

"Officials from the Consulate-General are in the Gunung Pulai area to assist the affected Singaporean families," said MFA.