By Steve Jackson
Billionaire Egyptian investor Naguib Sawiris is backing the venture
A giant Egyptian telecoms firm has launched the first hi-tech mobile phone network in North Korea.
Orascom telecom says it is investing $400m (£262m) in the service over four years.
North Korea is one of the world's most tightly controlled societies and it is still unclear who will be able to use the system.
The country launched a basic network in 2002 but most citizens have since been banned from using mobile phones.
Orascom telecom is one of the biggest operators of mobile phone networks in the Middle East and Africa.
The company surprised observers last January when it announced a joint venture with North Korea to set up a third generation mobile network there.
The system has now been launched in the capital, Pyongyang, by Orascom's billionaire chief executive Naguib Sawiris.
"The prospect of this company is to build a network that will accommodate the 22 million people in North Korea," he said.
He added that he was "surprised and astonished by the quality and advancement of the Korean people".
North Korea launched its own more basic mobile network in 2002, but has since banned the vast majority of its citizens and most foreigners from using it, allowing access only to senior government officials.
The new network will be able to provide fast internet connections and handle large quantities of information. However, that is a commodity the North Korean authorities have been extremely anxious to restrict.
Radios and televisions sold there have their tuning controls fixed to official stations and making phone calls out of North Korea is impossible for ordinary citizens.
Some reports suggest that handsets for the new network will cost around $700 each, putting them far beyond the reach of the vast majority of people in the impoverished country.
The United Nations estimates that nearly nine million North Koreans - or around 40% of the population - are in urgent need of food aid.