A popular service used to bypass Chinese internet restrictions has told users it is facing "increased censorship" in the wake of a major military parade in Beijing.
On Monday, virtual private network (VPN) provider Astrill sent a message to users of its iPhone app, informing them that the Great Firewall was blocking all VPN protocols "using machine learning".
The company did not respond to a request for comment.
"Due to upcoming Beijing's military parade next week, China is cracking down on IPSec VPNs using GFW auto-learning technique," Astrill said late last month.
That crackdown has now expanded to take in the widely used PPTP and L2TP protocols, according to the company's most recent statement.