Boko Haram leader Abubakar Shekau has threatened Cameroon in a video message on YouTube, warning that the same fate would befall the country as neighbouring Nigeria
The video, which was posted on January 5, is directly addressed to Cameroon's President Paul Biya after repeated fighting between militants and troops in the country's far north.
"Oh Paul Biya, if you don't stop this, your evil plot, you will taste what has befallen Nigeria... Your troops cannot do anything to us," Shekau said in Arabic.
It is first time Shekau has directly addressed Cameroon and is also the first admission that Boko Haram has been actively operating in the country.
Boko Haram fighters had in the past launched attacks on northeastern Nigeria from bases in Cameroon but recent months have seen an increase in strikes within the country.
Boko Haram, which began its violent insurgency in 2009, has taken over swathes of territory in three northeastern Nigerian states, and declared some towns as part of its Islamic caliphate.
Cameroon's far north has come increasingly into the group's firing line and on December 28, Yaounde deployed fighter jets against Boko Haram for the first time.
Biya personally ordered the air strike after the insurgents crossed the border and seized a military camp, the government said on December 29.
The aerial bombardment, hailed as a new phase in the counter-insurgency, forced the Islamists to flee, it added.
Cameroon's president has made a series of strong statements against Boko Haram and in October last year vowed to go after the group "until it's totally wiped out".
In May last year, he said that a Paris meeting of Nigeria's neighbours was designed to "declare war on Boko Haram".
But a key agreement at the summit to set up a regional force has yet to be implemented, with Cameroon increasingly vocal in its criticisms about the lack of a coordinated response to Boko Haram