Tibetans taking part in and affected by the continuing unrest have contacted the BBC News website to describe their experiences.
ANONYMOUS TIBETAN, HONGYAN COUNTY, ABA PREFECTURE, SICHUAN PROVINCE, CHINA
There have been many reports of injuries and deaths in Lhasa
I am inside a monastery right now. The telephone landlines have all been cut off. Just one minute ago [1345 GMT] there was a big commotion. The monks outside the monastery were shouting: 'Long Live the Dalai Lama!'
This morning the students of a middle school went out and protested. There were arrests and many Tibetans went to the police station to demand the release of those detained. Two girls were shot and wounded.
It is tense and frightening. The police later released the students.
In Barkham county there is a high school with a student population of about 300-400 students. These students managed to bring down the Chinese national flag.
ANONYMOUS TIBETAN PROTESTER, MACHU, GANSU PROVINCE
On Sunday at around 2pm, 200 people demonstrated in Machu county. Groups of people took down the Chinese flag, set it on fire and put the Tibetan flag up in its place.
In the evening, at around 4 or 5pm, a crowd of people went to government office buildings and set them on fire. Later on, the crowd set fire to the Public Security Bureau office.
Along the way, people were settling motorcycles and shops alight. I think they were Chinese-owned shops.
I was there. I saw it all.
In surrounding villages there have been small protests. In a small village called Ngura Xian I also took part in a silent candlelight vigil.
We did this to symbolise the hopes and aspirations of Tibetan people from under the dark period of Chinese rule. During the vigil, the police came and dispersed us.
We are protesting for many reasons. We know that this is the Olympic year for Beijing. Nations will come to China to represent themselves. We are protesting like this to express our national identity.
TIBETAN WHO WISHES TO REMAIN ANONYMOUS, LHASA
There is a heavy police presence and lots of military vehicles. I heard that there have been arrests and that two people were killed in the Tsangkhung nunnery.
On state television they're announcing that the situation is under control and the trouble-makers have surrendered. They also said a mosque had been burned but I only saw that the shops outside the mosque were burned and damaged.
I have been able to call people and I was allowed to go and visit the Tormzig Khang market, and wasn't challenged by the police. So I have been out.
The schools are now open and children are going to school but shops are still closed as lots have been damaged and burned.
What really worries me is that I can't see a single westerner or foreign journalist. That is of concern.
TIBETAN WHO WISHES TO REMAIN ANONYMOUS, OUTSIDE LHASA
The situation feels very tense and there is a heavy military presence. I saw large convoys moving towards Lhasa.
There are all kinds of rumours going around but it is difficult to know what to believe.
My family and friends are all very, very worried and fearful of the unknown and what might happen in the coming days.
We are very worried about arbitrary arrests. We believe that the people recorded on CCTV will get arrested but I fear that others will be arrested.
We are all very worried about the lack of western people and journalists in and around Lhasa. I have not seen any myself in the past day.