Charlie Hebdo: Police surround hostage warehouse

French police have surrounded a building in a northern town where two men suspected of the Charlie Hebdo massacre are said to have a hostage.

Shots were fired and several people are said to have been wounded as events unfolded in Dammartin-en-Goele, 35km (22 miles) from Paris.

The development comes nearly 48 hours after the attack on the magazine's office, when 12 people were shot dead.

The BBC's Chris Morris reports.