Malaysian Prime Minister Datuk Seri Najib Razak has expressed sadness over the fire tragedy at a residential religious school in Kuala Lumpur on Thursday that claimed the lives of 21 students and two teachers.

He also conveyed his condolences to the families of the victims of the fire that occurred at about 5 am (Malaysian time) at the Darul Quran Ittifaqiyah school in Jalan Keramat Ujung.

"I pray for their souls to be placed among the martyrs because their faith is strong," he said at a press conference after a meeting with the Prime Minister of the United Kingdom, Theresa May, at the latter's office at 10, Downing Street, here on Thursday.

Najib advised the management of tahfiz religious schools in Malaysia to give importance to the safety at the institutions by adhering strictly to all safety regulations imposed by the local authorities and Fire and Rescue Department to prevent a recurrence of such a tragedy.

The fire at the Darul Quran Ittifaqiyah school resulted in the deaths of the 23 students and teachers after they were trapped in the building that had grilles on the door and windows.

Najib had also tweeted on Thursday, as he concluded a visit to the United States where he met and conferred with US President Donald Trump, that he was saddened upon receiving news of the deaths at the school.

-- BERNAMA