"This is just the beginning." The Taliban responded with such a message after claiming responsibility for the attack on the house of Afghan Defense Minister General Bismillah Khan Mohammadi in Kabul yesterday.

"The suicide attack was just the beginning of a counterattack against key figures and leaders of the administration." Taliban spokesman Zabiul Mujahid said on Twitter.

The attack killed eight people and injured 20.

Earlier, an eyewitness and a police source in Kabul said a car had been blown up near the house of the Afghan defense minister in Kabul, after which several gunmen stormed the house. Mohammadi said neither he nor his family were injured. According to the Kabul police, gunmen also broke into the house of the member of the lower house of parliament, Azim Baglani.

The attack comes after the Taliban stepped up their campaign to defeat the US-backed government after foreign-led US forces ended their withdrawal from the region after 20 years of military presence.

Hours later, an explosion near the Afghan National Security Agency building in Kabul wounded three civilians and a member of the security forces.

In the meantime, some Kabulis took to the streets chanting Allahu Akbar (God is the Greatest), defying the militant attack.

Similar scenes took place on Monday in the city of Herat, where heavy fighting has also been taking place in recent days.

A public statement of defiance is a key boost to the fighting morale of Afghan forces in a bid to prevent militants from trying to take control of a number of provinces, the BBC reported.

However, the attack on the minister's house shows that the rebels can attack even in the very center of the government.

Civilians have been fleeing their homes in southern Afghanistan since yesterday as government troops prepare a counterattack to regain control of parts of Lashkar Gah, the capital of Helmand province, which has been at the center of US and British military campaigns, but it is unclear whether civilians they can do it safely.

The United Nations says at least 40 civilians were killed in the area on Tuesday.

Key parts of Lashkar Gah are controlled by the Taliban, who have reportedly surrounded local government buildings and banned government-backed electronic media.

Ataullah Afgan, head of Helmand provincial council, acknowledged at the weekend that the fighting seemed to be "out of our control".

The Taliban advanced this week, despite Afghan and US air strikes on their positions.

"There are corpses on the roads. "We do not know if they are civilians or the Taliban," an unnamed resident told the BBC.

"Dozens of families have fled their homes and settled near the Helmand River," the source said.