Imran Khan has started his march from Islamabad to Southern Waziristan, a dangerous tribal area of Pakistan currently the target of CIA drone attacks.
The march has been denounced by various Pakistani Taliban factions, but Khan insisted it would go ahead:
This is a peace march, an effort for peace in Pakistan on our part ... We are not going to fight anyone.
More top news
After a remarkably mild November - a notable mild start to the new month.
The Facebook founder revealed the plan as he and wife Priscilla Chan announced the birth of their baby daughter, Max.
At least 300 people are actively promoting and recruiting for the terror group from within the United States, academics have found.