People walk past the site of a suicide attack in Kabul, capital of Afghanistan, July 26, 2018. At least one Afghan civilian and four intelligence officers were killed and six others injured in a Taliban suicide car bomb explosion in western side of capital city Kabul on Thursday morning, police said. (Xinhua/Rahmat Alizadah)

At least one Afghan civilian and four intelligence officers were killed and six others injured in a Taliban suicide car bomb explosion in western side of Kabul on Thursday morning, police said.

"The latest information found that an assailant rammed an explosive-laden vehicle into a convoy of national intelligence forces in Bagh-i-Davod neighborhood, Police District 5 of the city, leaving the casualties," Hashmat Stanikzai, a Kabul police spokesman, told Xinhua.

The targeted multi-vehicle convoy was carrying Special Operations Forces of National Directorate of Security (NDS), the country's primary intelligence agency.

Among those injured was a passerby civilian, according to Stanikzai. Earlier reports said five NDS officers were killed in the attack.

"The incident occurred roughly at 4:45 a.m. local time. The whole place has now been sealed off and the massive blast also damaged several vehicles and nearby houses and shops," witness Mohammad Shafiq told Xinhua.

A thick black smoke was seen rise above the site and military helicopters were hovering at the area after the explosion, he added.

The Taliban militant group claimed responsibility shortly after the attack.

The violence has been on the rise as Afghan security forces struggle against a surge in attacks by anti-government fighters since the drawdown of foreign forces within the past three years.

The capital city has been hit by series of terror attacks over the past couple of years.

On Sunday, 23 people were killed and 107 others wounded after an Islamic State (IS) terrorist detonated his explosive jacket at a crowded traffic circle outside the capital's airport after a convoy of Afghan vice president passed the area.