Troops from Chad have arrived in Cameroon to fight the armed group Boko Haram just across the porous border it shares with in north eastern Nigeria.

Their convoy is now in the area of Maroua in Northern Cameroon.

Al Jazeera's Erica Wood has more a joint effort by Nigerian and Cameroonian and Chad troops against Boko Haram, the radical armed group fighting against western influence, that has claimed responsibility for numerous abductions and deaths in the region.