Nursery workers in the Qatar mall fire that killed 19 people, including New Zealand triplets, say they were ordered not to talk about it.

Two-year-old Lillie, Jackson and Willsher Weekes were among those killed in the fire at Villagio Mall in Doha on Monday.

They were in a nursery where 13 children died.

Local commentators have called for extensive safety reviews after the sprinkler system malfunctioned during the fire and there has been speculation that safety standards may have suffered in Qatar's massive building boom.

At the meeting in Doha on Friday, nursery workers said they understood people were evacuated from the rest of the mall before the nursery was even told there was a fire.

They said they had been ordered to stay silent.

"They told us not to speak. They told us not to talk about this on phone calls, in media, we cannot say anything," one worker told the public meeting.

Others at the meeting were angry about a lack of information in the state-controlled media, after Qatar TV refused to break into its normal broadcasting to report on the fire, while others raised concerns about the building standards in the country.

Sarrinah Undey was meant to drop her son at the nursery that morning, but she received a phone call from one of the trapped workers.

"She's crying and she tells me `we need help'. I told her `don't panic', then I could hear the children - they were shouting, then it's the end. I hear no more," Ms Undey told 3News.

Five people have so far been arrested over the fire.

The triplets' parents, Martin and Jane Weekes, have written an open letter, saying they are saddened by "misguided speculation and innuendo" which is being used to create blame.

"This process should not be about blame regardless of the hurt we all may feel now. This must be about learning so that no person need feel this pain again," they wrote.

"We want an understanding of what actually went wrong and how to ensure it never happens again."

The Weekes asked that experts be given time to properly investigate the fire, and that the Qatar government bring in international help, as such a disaster had never happened before in the Gulf state.