The number of mobile phones in use worldwide has topped five billion, boosted by soaring demand in emerging markets India and China, according to a study by Swedish telecoms group Ericsson.

The world's five billionth mobile phone subscription was recorded on July 8, the company said in a statement, with the market having increased almost seven-fold in 10 years.

"In the year 2000, about 720 million people had mobile subscriptions, less than the amount of users in China alone today," Ericsson said.