From Brussels to Lahore and Kabul, governments are struggling to stop violence carried out by extremist groups.

This week’s suicide bombing in Kabul, Afghanistan marked the deadliest attack by the Taliban in the Afghan capital since 2011.

Foreign fighters trained in the Middle East have also carried out violent attacks across Europe, most recently in Paris and Brussels.

We begin our coverage with CCTV’s Kate Parkinson from Paris.

For more on the fight against extremist groups we interviewed a panel of experts:

• Imtiaz Gul, executive director and founder of the Center for Research and Security Studies, based in Pakistan
• Daveed Gartenstein-Ross, senior fellow at the DC-based Foundation for Defense and Democracies
• Abdel Bari Atwan, founder and editor-in-chief of the Arabic news website, “Rai al-Youm.”