A suicide attack using a truck-bomb along a road in the Afghan capital of Kabul rocked the nearby Russian embassy on 20 January. The powerful blast killed four and wounded a further 24, Afghan media reported, citing deputy interior minister Basir Salangi.

Medical officials confirmed the number of dead and wounded to the Afghan outlet TV News 1, but there were no further details on the condition of the injured. Eyewitnesses reported the explosion shattered glass windows on nearby buildings and the road had been blocked as a precaution.

The Russian Foreign Ministry said the attack was not directed at its embassy, Interfax news agency reported. According to AFP the bomb targeted a bus carrying employees from the popular Afghan TV series TOLO. "Our office bus taking TOLO staff home came under attack," a reporter at the channel was quoted as saying under condition of anonymity.

Reuters cited police sources that confirmed a "loud explosion" at around 5pm local time, adding several vehicles surrounding the blast site had been damaged. No group has claimed responsibility for the attack.

Images emerged on social media showing pictures of the blast. One picture showed the fiery wreckage of the aftermath near a central reservation of what appeared to be a central Kabul thoroughfare. The roads appeared relatively empty.

The attack in Kabul is the sixth such bomb attack in the Afghan capital this year. Two members of the security forces were injured on Sunday (17 January) when a rocket landed near the Italian embassy.

Government forces in Afghanistan have struggled to fend off a resurgent Taliban threat, particularly in Helmand province. The Taliban heartland and the strategically crucial town of Sangin were on the cusp of falling to the radical group prior to a last-minute intervention by US and British forces.

Afghan police and the country's army have called for reinforcements in the wake of the Taliban attacks, with security forces overwhelmed.

The blast in Kabul follows Taliban violence in Pakistan where at least 21 people have been killed after militants opened fire and hurled explosives at Bacha Khan University in Charsadda, north-west Pakistan. A military operation to stop the attackers continued for four hours after the siege began.