It was the Dalai Lama’s birthday last week; he turned 77. China celebrated in its own unique way by severing public communication services, with both text messaging and internet access disabled for two days in Ganzi prefecture, a Tibetan autonomous region in western Sichuan province. Phone calls, however, could still be made.

There was no announcement, no explanation. One minute you could surf the internet, text your friend; the next, messages were blocked and the web was down.

The rumours ran wild as to what had happened.

“It’s a bit sensitive,” said one Han Chinese guy who had settled in Sequ town in Ganzi after marrying a local girl. “We’d better not talk about it.”

One 17-year-old Tibetan teenager whispered: “I heard there was some kind of protest in Ganzi Town or Xinlong Town so they cut us off.”

Ganzi town is notorious for its restiveness — Tibetans regularly distribute leaflets calling for the return of the Dalai Lama and get into scuffles with the police. The town is often out of bounds to foreign tourists during particularly restive times. But such an extreme measure — cutting the internet and phone messaging services —  implied something much more serious. The authorities only resort to this if they are afraid of people organising a mass protest or disseminating photos and information.

I called friends across the prefecture in Luhuo, in Litang and in Daofu. Everywhere in Ganzi the internet was down. And no one knew why. Qinghai, the other main Chinese province in with large Tibetan populations stayed online, however.

“There are lots of foreigners on the grasslands,” mused my Luhuo friend. “So I don’t think anything big has happened.”

Internet and phone messaging services were cut off earlier this year for several months after a string of protests and fights with the police in several towns in Ganzi. The longest and most well-known severing of communication channels was in the Xinjiang region in 2009 after deadly riots in Urumqi. It took 10 months for the Uighur autonomous region to get its internet back.

But back in Ganzi, two days later and out of the blue, connections were re-established. Again, with no announcement, no explanation.

Then it became clear: it was simply a precaution in case Tibetans used the occasion of the Dalai Lama’s birthday to organise “something special”.

One Weibo (China’s answer to Twitter) user posted a comment by Woeser, an outspoken Tibetan writer living in Beijing:

In order to celebrate the Dalai Lama’s birthday yesterday all Tibetan areas had their Internet cut, including Ganzi’s Xinduqiao, Yajiang, Litang. There was no mobile Internet service or messaging service, and so I wasted a lot of money calling my old classmates in Tibet and Sichuan. It wasn’t until midday today that I found out the reason for the stoppage.  It wasn’t a problem with my phone, it wasn’t a problem with China Mobile; it was a problem with the ZF [government].

The author has requested this article be published anonymously