A British recruiter with the Islamic State (IS) terror group in Syria is grooming youngsters through secret internet messages featuring kittens with bombs.

Omar Hussain has been using an encrypted smartphone app to draw in impressionable followers with cute images of cats paired with terror lectures, the Sunday Times reported.

The 28-year-old recently posted a photograph of a kitten curled up inside a suicide explosives belt.

Alongside it he wrote "Come closer and I'll blow the entire house down!" Another picture featured a cat called Bint Lucy snuggled up against a hand grenade.

Separately Hussain, a former security guard at Morrisons supermarket in High Wycombe, south-east England, posted a message on hating the "kuffar", or non-believers.

"It is an essential part of our religion. A Muslim cannot claim to love Islam while simultaneously having no hatred for the kuffar," he claimed.

Experts believe Hussain may be deliberately deploying an IS strategy aimed at brainwashing or grooming teenagers and young people.

He has been spreading propaganda on the encrypted Telegram app after having his Twitter and Tumblr accounts repeatedly suspended.

By Friday his posts were being followed and read by almost 800 extremists, the newspaper found.

In one message Hussain, who has appeared in IS propaganda videos in the past, posted a photograph of an assault rifle with the caption, "Jihad is so fun. Go around killing kafirs, taking their stuff. It's a dream job. Lol".