A suicide bomber has rammed a car packed with explosives into a police truck outside a bakery in southern Afghanistan, killing at least two civilians, officials said. The attacker was apparently waiting in the car at the gates of the police headquarters just outside a bakery where officers regularly buy bread in the morning in Lashkar Gah, the main city in Helmand province, said provincial Police Chief Kamaluddin Sherzai. The bomber slammed the vehicle into a police truck that was parked at the shop, triggering the car\'s explosives, he said. Two civilians were killed in the blast - a man and a young boy, said provincial government spokesman Daoud Ahmadi. Another 26 people were injured, including 10 police officers and six children, he said. Taliban spokesman Qari Yousef Ahmadi claimed responsibility for the attack, which came hours after the Taliban released a formal statement rejecting claims that they have become splintered or that they or any of their allies have ties to the Pakistani government. The Taliban said their insurgency \"is at its strongest and unified more than it has been at any other stage\", and denied that they have bases in Pakistan. The claim runs contrary to US and international assertions that the Taliban retain numerous safe havens and bases in Pakistan\'s tribal areas, used to stage attacks into neighbouring Afghanistan. The Taliban also reject US charges that the Haqqani network, a key affiliate, has ties to Pakistan\'s intelligence service. The group says Haqqani network founder Jalaluddin Haqqani is a key member of the Taliban leadership. The Taliban statement appears to be an attempt to give the Pakistani government some breathing room as Islamabad comes under increasing pressure to take action against insurgents within its borders. Nato forces spokesman Brigadier General Carsten Jacobson said on Monday that the Haqqani network is still very much operating out of Pakistan: \"We have no credible intelligence indicating that the Haqqani network has eliminated their operating safe havens in Pakistan.\"