CNN reports: 

Another Lhasa resident, who also withheld his name, said his electricity and telephone service had been cut off. He spoke to CNN on his cell phone.

China continues to impose reporting restrictions in Tibet and the neighboring province of Xinjiang. CNN sought permission to enter Tibet on Friday morning Beijing time. So far, this perrmission has not been granted. CNN reporting on Tibet was being blacked out Friday in mainland China.

CNN also quoted a Han Chinese tourist as saying that China has shut down trains out of Tibet.