UK food and health campaigners have accused snack manufacturers of "shamelessly" targeting children with online games, apps and social media.

The British Heart Foundation and The Children's Food Campaign have claimed food makers are "bombarding" kids with online marketing to push products that are high in fat, salt and sugar. It has called for consistent advertising regulations across all forms of media.

The Advertising Standards Authority has guidelines stating that food that is high in fat, salt or sugar cannot be advertised on TV channels or programmes intended for children. However, the BHF argues rules on online marketing are "weak" and open to interpretation.

BHF policy manager Mubeen Bhutta said: "Like wolves in sheep's clothing, junk food manufacturers are preying on children and targeting them with fun and games they know will hold their attention. Regulation protects our children from these cynical marketing tactics while they're watching their favourite children's TV programmes but there is no protection when they're online. With around a third of children classified as overweight or obese today it's crucial that the UK government takes action."

The report cites manufacturers including Kerry Group, Kraft Foods, Kellogg and Nestle for using online marketing campaigns to target children.

Nestle, which faced criticism over its marketing of its Nesquik products, said it has "strict policies" regarding marketing and advertising to children. A spokesperson claimed a resource called 'Imagination Station' on its Facebook page is intended for parents.

Irish food group Kerry found its marketing of its Cheestrings under scrutiny. The BHF claimed one portion of Cheestrings contained more salt than a packet of crisps. However, Kerry defended its product, insisting it was 100% cheese and a source of calcium and that the salt content of Cheestrings was in line with natural cheddar cheese.

"We are firm believers in responsible marketing and we ensure that everything we do is within the regulations set by the various governing bodies," a spokesperson said added.

A spokesman from the ASA said complaints on this issue were "very low" but said it has noted the BHF's report.

"The rules are very clear: ads must not condone or encourage poor nutritional habits or an unhealthy lifestyle in children," he added.