A magnitude 7 earthquake has struck Tibet, and relief work is now under way across the region. Rescue teams are combing through damaged buildings and moving people to safer ground. Tents and medical supplies are being rushed to the communities hit by the quake. The mountainous terrain is slowing the movement of emergency crews trying to reach isolated spots. Officials have not yet released a full count of casualties or structural damage. Aftershocks are keeping residents on edge as assessment teams move from one settlement to the next. A clearer picture of the destruction should emerge once rescuers reach the more remote villages. Aid agencies are standing by for requests as the scale of the damage becomes clearer.