AFP, Kabul :Multiple bombings rocked Kabul Friday, killing at least 42 people and wounding hundreds more in the deadliest day in the Afghan capital since the end of the NATO combat mission in December.The explosions, which devastated buildings and overwhelmed hospitals with casualties, are the first major militant assaults on Kabul since the announcement of Taliban leader Mullah Omar’s death. In the first attack, a powerful truck bomb tore through the centre of Kabul just after midnight on Friday, killing 15 civilians and wounding 240 others.Less than 24 hours later, at least 20 Afghan cadets were killed when a suicide attacker dressed in police uniform blew himself up at the entrance of Kabul Police Academy.The Taliban distanced themselves from the first bombing that struck near a Kabul military base — as they usually do in attacks that result in a large number of civilian casualties.But the insurgents were quick to claim responsibility for the second attack, which marks a serious breach of security at a premier training institute for Afghan security forces.Explosions and gunfire also erupted when Camp Integrity, a base near the airport housing US special forces, came under attack late Friday, killing one NATO service member whose nationality was not revealed.Military jets were heard flying over the centre of Kabul shortly after the explosions.The carnage underscores the volatile security situation in Afghanistan amid a faltering peace process with the Taliban as Afghan forces face their first summer fighting season without full NATO support.Friday’s bombings are the first major attacks after Mullah Akhtar Mansour was last week named as the new Taliban chief in an acrimonious power transition after the insurgents confirmed the death of longtime leader Mullah Omar. Observers say the escalating violence demonstrates Mullah Mansour’s attempt to boost his image among Taliban cadres and drive attention away from internal divisions over his leadership.”The new wave of attacks is a tactic by the Taliban’s new leadership to show they are capable, potent and operational,” said security analyst Abdul Hadi Khaled. “The demise of Mullah Omar divided the movement and affected the morale of their ground fighters. Hitting Kabul with a wave of powerful attacks is a way of showcasing their strength.”On Friday evening, a suicide attacker dressed in police uniform blew himself up at the entrance of Kabul Police Academy, killing at least 20 Afghan cadets who were returning after their two-day weekend.”The attacker was wearing police uniform… when he detonated his explosives, 20 cadets were killed and 20 more were wounded,” the official told AFP. Anguished relatives of cadets gathered near the academy, which was cordoned off by heavily-armed security officials as ambulances with wailing sirens rushed to the scene.