By Usman Sharifi
At least 12 people including three US civilian contractors have been killed after a suicide car bomber struck a NATO convoy, officials say, underlining the precarious security situation in the Afghan capital.
The Taliban denied responsibility for Saturday's blast, which struck outside a civilian hospital in Kabul following a wave of fatal bombings earlier this month that rattled the city.
The piercing explosion in a crowded residential neighbourhood reverberated around Kabul and left a trail of devastation, including twisted wreckage of burning vehicles with officials seen piling up bloodied bodies in a police pickup truck.
The blast killed 12 people and wounded 66 others, health ministry spokesman Wahidullah Mayar said on Twitter.
Senior health official Sayed Kabir Amiri confirmed the toll from the attack, which comes as Taliban insurgents escalate their annual summer offensive against the US-backed Afghan government amid faltering peace talks.
"One Resolute Support (NATO) US contractor was killed and two Resolute Support US contractors died of wounds as a result of an... attack on their convoy in Kabul," NATO said in a statement.
"Instead of seizing an opportunity to embrace peace, insurgents have again chosen violence in an attempt to remain relevant," a separate NATO statement said.
US-led NATO forces ended their combat mission in Afghanistan in December last year, although a 13,000-strong residual force remains for training and counter-terrorism operations.
Taliban spokesman Zabiullah Mujahid said the group was not behind the attack, which prompted the heavily-fortified US embassy, located a few kilometres (miles) away in the centre of Kabul, to sound its emergency sirens and a "duck and cover" alarm warning.
The insurgents are known to distance themselves from attacks that result in a large number of civilian casualties.
"The mujahideen had no plan for an attack in Kabul today," Mujahid said.