North Korea has suspended a cell-phone rental service for visiting foreigners, according to Japan’s Kyodo News.

The suspension began in January and could, speculates Kyodo, “reflect concern in the North over the flow of information about democracy demonstrations sweeping the Middle East.”

Telecommunications systems, including cell phones and the Internet, have proved instrumental in the growing civil unrest that has already engulfed several Middle Eastern states. In Egypt the government shut off both networks at the height of the unrest.

North Koreans don’t have access to the Internet, but at least 300,000 of them carry cell phones, according to data from the operator. Koryolink, a joint venture of Egypt’s Orascom and the DPRK’s telecommunications authority, started service in late 2008 and has seen strong subscriber growth.

Visiting foreigners must surrender cell phones at the airport, but rental phones have been available. Kyodo said that cell phone rentals have now been restricted to resident foreigners.

The phones are capable of making international calls, but are understood to be restricted from connecting with most domestic cell phones.

Typically cell phone networks in North Korea restrict calls between the resident foreign population and citizens. Foreigners can make international calls and reach each other but not private lines owned by citizens. Citizens can call each other but not connect with handsets owned by foreigners or make international calls.

Orascom said in early 2009 that the North Korean government had the ability to monitor calls make over the network.