Blast in Kabul as Taliban battle government forces in south, west

An explosion near a facility of Afghanistan's main security agency in the capital, Kabul, on Wednesday, wounded two civilians and a security official, police said.

The blast near a National Directorate of Security compound came hours after a car bomb and clashes near Kabul's diplomatic district, in which eight people including four attackers were killed.

There was no claim of responsibility for the Wednesday blast or the late Tuesday attack but they come as the Taliban have stepped up their campaign to defeat the U.S.-backed government as US-led foreign forces complete their withdrawal after 20 years of war.

Fighting has been particularly heavy around the city of Herat, near the western border with Iran, and Lashkar Gah and Kandahar in the south.

Read: Car bomb hits near Kabul 'Green Zone'

The late Tuesday bomb-and-gun attack in Kabul was aimed at acting Defence Minister Bismillah Mohammadi and other politicians. Government forces battled the unidentified gunmen for more than four hours. Mohammadi survived.

An Afghan military spokesman said an emergency had been declared in Lashkar Gah and government forces were getting reinforcements and US air support.

"Special forces have been sent to the area. They are in good morale," armed forces spokesman General Ajmal Omar Shinwari told Reuters.

The loss of Lashkar Gah would be a huge blow for the government, which has pledged to defend strategic centres after losing many rural districts to the Taliban in recent months.

Scores of families have fled from their homes in the small city, capital of Helmand province, as government forces launched a counterattack against the Taliban.

The United Nations reported Tuesday that at least 40 civilians had been killed in Lashkar Gah in the previous 24 hours.

Taliban fighters had taken control of some radio and TV stations in the city and were moving into homes to stop people from helping government forces, residents said.