KABUL, Aug 3 (Reuters) - A car bomb blast followed by sporadic gunfire hit Afghanistan"s capital Kabul on Tuesday near the heavily fortified "Green Zone", leaving three civilians and three attackers dead, security officials said amid an upturn in violence by Taliban militants. At least seven other people were wounded, said health ministry spokesperson Ghulam Dastagir Nazari. An interior ministry spokesperson said security forces" operations ended with the death of all attackers. A senior security official said the blast appeared to have been caused by a car bomb and the target was the acting defence minister"s home and the adjoining residence of a member of parliament. The attack – in the heart of one of Kabul"s most secure areas - came during an escalation in violence by the Taliban. Attacks have risen sharply since President Joe Biden announced U.S. troops would leave by September even as the Taliban intensified its attacks on major cities. Three unidentified gunmen were killed at Tuesday"s attack site which is home to Afghan officials, lawmakers and prominent residents. No group immediately claimed responsibility. Minutes after the blast, hundreds of civilians in Kabul came out on to the streets and chanted Allahu Akbar (God is Greatest) to express their support for Afghan government forces and opposition to the Taliban. The night-time march spilled across the city with mostly men and some women joining in the demonstrations, carrying candles and Afghan flags to signal united opposition to the hardline Islamist group. "The whole world can choose to be silent about what is going on in Afghanistan but we can"t and won"t stay quiet anymore...we will stand side by side with our security forces until our last breath," said a demonstrator in Kabul on condition of anonymity. The country"s first Vice President Amrullah Saleh said the demonstrations were "historic moments" of "emotions and patriotism." "Allah o Akbar, death to Talib terrorists & their backer," he said in a tweet at a time when Afghan forces flushed out militants in the overnight operations. Last week, residents in the western province of Herat braved the streets despite nearby fighting to protest against the Taliban. Other cities quickly organised to join from their homes in the evenings, as a message of support for embattled security forces. After Tuesday"s bomb attack, acting Defence Minister Bismillah Mohammadi said no harm was caused to him and his family members but some of his security guards were injured. A Kabul police spokesperson said at least 30 civilians had been rescued from the blast site. The city"s Emergency Hospital said in a tweet it had so far received 11 people wounded in the attack. Afghan forces appealed to residents of the southern city of Lashkar Gah to leave their homes and stay away from areas where the Taliban were taking control, as they intend to launch operations against the group where its fighters were travelling freely. The loss of Lashkar Gah would be a huge strategic defeat for the government, which has pledged to defend strategic centres after losing much of the rural parts to the Taliban in recent months. The Taliban said their fighters killed a district governor of central Maidan Wardak province on Tuesday, the latest in a series of killings by the insurgent group aimed at eliminating senior government officials and social activists.