KADUNA: The leader of Boko Haram Islamist rebels said on Wednesday that the Nigerian military offensive is failing in its goal of crushing the four-year-old insurgency.

Abubakar Shekau's statement, in a video seen by Reuters, was the first word from Boko Haram since President Goodluck Jonathan declared a state of emergency on May 14 in the three northeastern states worst hit by the insurgency.

Thousands of extra troops were sent to the region and Boko Haram camps were hit with air strikes. The military has since claimed that insurgents have been halted.

Shekau denied he was losing the battle.

“My fellow brethren from all over the world I assure you that we are strong, hail and hearty since they launched this assault on us following the state of emergency declaration,” he said, dressed in camouflage with an AK-47 rifle resting behind him.

“When they launch any attack on us you see soldiers fleeing and throwing away their weapons like a rabbit that is been hunted down,” he added, speaking in a mixture of Arabic and the Hausa language common in northern Nigeria.

Shekau asked his “brethren” in Iraq, Pakistan, Afghanistan and Syria to join what he called Boko Haram's Holy War.

The video goes on to show apparently dead bodies in military uniform and charred camouflaged vehicles which Shekau said were evidence of victories in clashes with soldiers.

The military assault in the semi-deserts along the borders with Cameroon, Chad and Niger is Jonathan's biggest effort yet to end the insurgency. Security sources said soldiers from Niger and Cameroon are also involved.

It follows a surge in violence in Nigeria's northeast by Boko Haram, which wants to establish an Islamic state there.

Nigeria's population of 170 million is split roughly evenly between Christians, who dominate in the south, and Muslims, who are the majority in the north.

The military has said it has arrested more than 100 insurgents, freed hostages and killed several Boko Haram members in recent days. But its statements made no mention of the sort of counter-strikes Boko Haram have launched in the past.

Shekau said only seven Boko Haram members have been killed since the offensive began.

The Defence Ministry said last week that the insurgents had been dislodged but security experts doubt it will be easy to defeat an enemy adept at re-arming and counter-attacking in remote regions where they have operated in for years.

It has been impossible to verify the claims of Shekau or the military because telephone services have been disconnected for 12 days in Borno state, where the bulk of the fighting has taken place.

Jonathan said last week he would free a number of detained Islamist suspects, mostly women and children, in what security sources believe was a move to build popular support. He has also offered amnesty to insurgents who lay down their weapons.