Radio Free Asia (RFA) says that foreigners visiting North Korea are no longer able to rent mobile phones due to a government order.

The Washington-funded broadcaster says the ban could be linked to concerns about information flow related to the pro-democracy uprisings in Arab states.

RFA says Pyongyang is believed to be wary of the inflow and circulation of information from abroad, as such information could lead to a call for regime change in North Korea.

It also cited a college student in Hyesan, Yanggang Province, as saying that news of regimes overturned by public uprisings in Africa and the Middle East are spreading among North Koreans via mobile and fixed-line phones.

Quoting a source in North Hamgyeong Province, RFA says that North Korean authorities have blocked cellular networks and have even suspended, for the time being, fixed-line services in people's homes.

Surveillance has also reportedly been tightened, with more security officers present at markets and schools.