BRUSSELS: Nato Secretary General Anders Fogh Rasmussen on Saturday urged Pakistan to stand united with its Western allies to tackle extremists, who were behind a double suicide bombing in the country.

“It is with shock and sadness that I learned the death of some 80 paramilitary cadets killed in a terrorist attack,” Rasmussen wrote in a letter to Pakistani President Asif Ali Zardari.

“This attack is a stark reminder that Pakistan and Allies must stand united to defeat the scourge of violent extremism,” he added.

The death toll rose to 89 following Friday's suicide bombing on a paramilitary police training centre in the town of Shabqadar in northwest Pakistan. Around 140 people were also wounded, 40 of them critically.

Pakistani Taliban has claimed responsibility for the attack, saying it was to avenge the death of Al Qaeda leader Osama bin Laden at the hands of US forces two weeks ago.

It was the deadliest attack this year in the nuclear-armed country, whose government is in crisis over the US raid on a compound in the northwestern city of Abbottabad where bin Laden had reportedly been hiding for five years.