Facebook is not working on PTCL and ping to facebook.com gives request time out.
Facebook is not available in Pakistan for last many hours.
There are few other websites which are unable such as all the blogs at subdomain of wordpress.com
This started early in the morning of thursday, 17th november 2011.
Are you experiencing facebook not loading in Pakistan too? What’s your city and network?
Confirming that Facebook is not working in:
Cities: Islamabad, Lahore, Karachi
Network: PTCL, witribe, warid
Update 2 :
Facebook is back up for me now in Islamabad on PTCL