A bomber detonated a car strapped with explosives in front of Kandahar University on Monday evening, killing at least seven people and injuring 23 others, local officials said. 

The assailant might be a student in Kandahar University who turned a suicide bomber and he might have planned to carry out the attack against foreign convoys but before reaching his target the bomb exploded in front of the University… All these possibilities are open, but so far it is not clear who and why this explosion occurred in front of the University and police has already began an investigation into the circumstances of the accident.

The Toyota Corolla used in the attack was in a parking area for cars in front of the university which is in Afghanistan's southern Kandahar province's capital city, Kandahar provincial spokesperson Jawed Faisal said.

The bomber detonated the explosives close to 7pm, Faisal said.

The provincial police chief confirmed the attack and the casualties.

Meanwhile two people were killed and at least 28 others were injured in an explosion in Afghanistan's capital city Kabul around midday on Tuesday, officials said. the number might rise.

Police said the source of the explosion was a gas tank inside a building of Kabul's Khair Khana district which is used to store and sell medical supplies in Shamshad market.

The possibility of other explosives being involved has not been ruled out, but the police said there was no Taliban activity in the area at the time.

At least five of those injured are in a critical state, according to officials.

Witnesses said that the explosion was very big and it damaged several cars parked outside the building.

The fire department told reporters at the scene that the fire was under control, but there were still people trapped inside the building.

In another incident an Australian soldier was killed in Taliban attack in southern Afghanistan, the alliance said on Tuesday.

In line with its policy, the NATO-led force neither revealed the soldier’s nationality nor the exact location of the assault that occurred on Monday.

But the Australian defence ministry announced that one of its soldiers was killed in a militant attack in the Chura district of Uruzgan province.

Australia has 1,500 soldiers in Afghanistan mostly stationed in Uruzgan. Since the occupation of Afghanistan nearly over decade, 33 Australian soldiers have been killed.

And Kabul police claims that a group which was planning to assassinate the Afghan warlord Ustaz Sayyaf was detained.