They entered the compound of the embassy at 12.50pm and left about 15 minutes later.

They refused to comment on the visit when met by reporters. One of them, an assistant superintendant, said: “You should ask my boss. You can maybe wait for my boss to give a statement.”

Their visit came about one hour before Deputy Prime Minister and Home Minister Ahmad Zahid Hamidi confirmed at a press conference that the man using the name Kim Chol killed at klia2 was indeed Kim Jong Nam, the estranged half-brother of North Korean leader Kim Jong-un.

Several cars bearing embassy number plates went in and out of the premises but the place was otherwise quiet. The ambassador was nowhere to be seen and reporters were not allowed in.

This morning, the embassy received about 40 visitors, several of whom were wearing traditional Korean costumes. When approached, none were willing to talk.

A minor commotion occurred when a foreign journalist entered the compound and took pictures of the interior of the house from the open front door with his smartphone.

An embassy officer grabbed the phone from him, deleted the pictures and returned it to the journalist. They shook hands before the journalist left the compound.

Kim Jong-nam was at the klia2 on Monday about 8am waiting for his flight to Macau when a woman covered his face with a cloth, said to be laced with poison. He died en route to the hospital in Putrajaya.

He is believed to have arrived in Malaysia from Macau on Feb 6. He was travelling on a North Korean passport bearing the name Kim Chol.

Police have detained two women and a man, with more arrests expected.

Security has been tightened at all entry points in the country following the killing of Jong Nam.

Selangor police chief Abdul Samah Mat said the measures included tighter surveillance at passenger entry-exit points at KLIA and klia2.

This is to prevent other suspects in the case from fleeing the country, he said.

He said the authorities were looking at the case from all angles, including trying to find out if others were involved.

“We are also waiting for a response from the North Korean Embassy in Malaysia on information we requested to help in the investigation into the case,” he said.

The Indonesian Embassy here has sought the permission of the foreign ministry to meet the woman bearing an Indonesian passport who was arrested over the killing of Jong-nam.

Minister-Counsellor at the Information, Social and Cultural Division of the embassy, Trigustono Supriyanto, said the meeting was to verify the identity of the woman and the authenticity of her passport.

“I received a WhatsApp message from a friend on the arrest of a woman bearing the passport of our country. There was no official information from the Malaysian authorities.

“Soon after getting the message, we contacted the Malaysian foreign ministry and are awaiting a response from them,” he said at his office.

He said until embassy officials met the woman, the embassy would be unable to verify her identity.

Inspector-General of Police Khalid Abu Bakar, in a statement, said a woman by the name of Siti Aishah, born in Serang, Indonesia, on Feb 11, 1992, was arrested early today. She had an Indonesian passport.

Siti Aishah is the second woman to have been arrested over the killing.

Another woman, identified as Doan Thi Huong, 29, and who had a Vietnamese passport, was arrested at klia2 at 8.20am yesterday.

About 100 local and international media representatives gathered at the Sultan Salahuddin Abdul Aziz Shah Courts Complex in Shah Alam from as early as 7am today to cover the remand of the suspects.

After waiting four hours, they learnt that the two women had been taken to the Sepang police headquarters where a magistrate issued a seven-day remand order to detain the foreigners to facilitate investigations.

The Chemistry Department today received for analysis several samples of a product from the police conducting investigations.

The director of the department’s Forensics Division, Dr Cornelia Charito Siricord, said the samples were received this evening and would be analysed as soon as possible.