Babies and toddlers are showing signs of addiction to smartphones and tablets, according to new research.

A team from Birmingham University has conducted the first study of the effect of regular use of touch-screen devices by children under the age of three.

With a range of apps teaching skills including literacy and numeracy aimed at young children now on the market, initial results indicate that the devices may affect the concentration and moods of children.

The US government advises that children younger than two should not use the devices, but there are no equivalent guidelines in the UK.

"Babies can drag and tap from a few months old and are able to interact with technology in a way which was impossible until a couple of years ago," said Dr Jane O'Connor, a senior researcher in education.

O'Connor said she decided to initiate the study after using an iPad app to help potty train her son, and was shocked to discover that no studies had been conducted of the effect of the devices on young children.

"This is a seismic change and uncharted territory in terms of their psychological, educational, social and psychological development," said O'Connor.

"It is in the interests of technology companies to aggressively market devices and apps to families with young children because they want to ensure that the next generation is securely attached to their products. Whether this is actually beneficial has become somewhat lost in the thrill of the new."

As part of the study, 300 parents of children under three answered questions in an online survey about the effect of the devices on their children.

It showed that on average parents allowed their children to play with the devices for 10 to 30 minutes a day, and for up to four hours on weekends.

"The fear of addiction is strong, with a lot of parents worried about the effect on their children's eyesight or concentration levels," said O'Connor.

One parent summed a common experience "My son's reaction when it's removed is worrying."

Parents who said they banned their children using the devices said that they believed it would enhance their childhood, while those who allowed their children to use them said that they thought it would give their children an advantage in the future.