Let's be blunt about this: China is targeted buy Islamic terror groups. There is no point in beating around the bush - if you want to fight them you have to name them. Most of these groups are training in Pakistan, and their members have been indoctrinated in local deobandi and wahhabi madrasas , funded with Saudi money. Pakistani authorities are turning blind eye because they to receive generous "donations" from Saudis. China basically has two options: 1. either to pressure Pakistani government to do something about this or 2. to reconsider its special relationship with this country.
Or option 3, use that special relationship to get Pakistan to do something about it, while at the same time not making a public spectical of doing so to avoid embarressing the Pakistanis.
And FYI, its not just the Pakistani government that China has a special relationship with, if anything, the Pakistani people are more friendly towards China.
In that regard, I hold serious reservations about just where these terrorists got their training and funding, because it has been reported in the past that Uighur terrorist wannabes were shunned, turned away, or even reported to the authories when they tried to get training in Pakistan, since the Pakistani Taliban knew that they wanted to kill Chinese. I just do not see that changing now.
The US has been accusing the Pakistanis of hosting terrorist training camps in their tribal areas for over a decade now. If they were willing to train Uighurs, it seems distinctly odd that terrorist attacks in China have been largely low-tech, low-impact and target mainly government and security forces until this recent wave.
Pakistan just doesn't fit and doesn't make sense. But somewhere else does fit, and makes perfect sense, and that's Syria and Turkey.
Much of Syria is now a lawless jihadi wonderland, where terrorist wannabes could not only get training and equipment, but also get real combat experience fighting against a 3rd rate government army, so they stand a decent chance of surviving long enough to accumulate a decent amount of experience and know how before returning home.
Its also the worst kept secret in the world that Turkey hosts training camps for jihadist and terrorists wanting to fight Assad, and the Turks are far more likely to be sympathetic towards Uighurs and train them than the Pakistanis. Erdogan himself made some pretty inflamitory, and frankly, stupid comments during the mass riots in Xinjiang. He back peddled pretty quickly when it became blatantly obvious how wrong he was, but it showed his bias and sympathies clearly.
If I was in charge of counter terrorism in China, I would be looking long and hard at the Syrian and Turkish connection rather than assume the western default setting of blaming Paksitan for everything terrorism related.