The children of Moray woman Arlene Fraser, who vanished without trace 10 days ago, yesterday begged her to get in touch with the message: ''Mummy we are missing you.'' However, they made their appeal as police became more convinced that her disappearance is the result of a criminal act, writes Graeme Smith.

They have now confirmed that a fire in her Ford Sierra car when it was parked in the drive of her New Elgin home last month is being treated as suspicious.

Mrs Fraser, 33, a business studies student at Moray College in Elgin, is separated from her husband Nat, 39, a fruit and vegetable wholesaler who is on bail after appearing at Elgin Sheriff Court accused of attempting to murder his wife around two months ago.

Mrs Fraser was last seen at 8.50am on Tuesday of last week by her two children, Jamie, 10, and Natalie, five, as she waved them off to school.

Since then, there has been no sighting of her. Her bungalow in Smith Street was found with the door unlocked and inside was ''as if she had just popped out to the shops''.

Her two children are becoming increasingly worried about their mother in spite of efforts by their grandparents to shield them as much as possible. Their grandmother, Mrs Isobel Thomson, 54, said yesterday that they were not sleeping and they were becoming withdrawn.

''They seem to be OK on the outside but we cannot really tell what Jamie is thinking.

''He took a long time to go to sleep last night. He appeared to be sleeping but this morning he said he hadn't been. Obviously he is feeling a lot more than he is letting us believe. They know their mother is missing. Missing to them means she has gone away for a few days. They do not realise the seriousness of it.''

She said they had been trying to protect the children from frequent visits by the police and press. However, the children have heard snatches of news bulletins and their schoolfriends have been chatting to them about their mother's disappearance.

The officer in charge of the inquiry, Detective Inspector Peter Simpson, admitted yesterday: ''I have severe concerns for her safety. Obviously when you get so long into an inquiry with no positive sightings of her and no contact from her then realistically you tend to think something criminal has happened to her.''

He said the speculative searches and the door-to-door inquiries have stopped and the team was beginning to work through a great deal of information they have gathered.