An Afghan doctor helps an injured woman after a suicide car bomb attack near a district police headquarters in the centre of the Afghan capital Kabul on March 25, 2015. A suicide attacker killed at least seven people after detonating the car bomb, officials said. The powerful blast went off in Muradkhani district close to the presidential palace, the defence ministry and the ministry of finance. (Photo by Wakil Kohsar/AFP Photo)

An Afghan policeman carries a wounded man at the site of a suicide attack in Kabul March 25, 2015. Six people were killed and more than 30 injured in the suicide bombing in the Afghan capital on Wednesday that struck close to the presidential palace in the heart of the city, the Interior Ministry said. The suicide bomber had been travelling in a vehicle packed with explosives and it was not immediately clear what the target of the attack had been. (Photo by Omar Sobhani/Reuters)

Afghan security forces inspect the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

A member of the Afghan security forces investigates at the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

Afghan security forces inspect the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

Afghan police arrive at the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

Afghan security forces inspect the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

An Afghan woman shows a damaged wall of a shrine after a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

Afghan security forces inspect the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

An Afghan National Army (ANA) soldier keeps watch at the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

Afghan residents look as security forces inspect the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

A man prepares to drive a damaged car away from the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

Afghan security forces inspect the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

An Afghan man drives his damaged car away from site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

An Afghan girl sweeps debris of a damaged wall of a shrine after a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

Afghan policemen inspect the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

Afghan policemen are seen through a cracked window of a vehicle at the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

An Afghan security force inspects the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

People gather at the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

An Afghan girl looks out as she stands inside of a damaged shrine after a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

People gather at the site of a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)

An Afghan girl looks out of a damaged window of a shrine after a suicide attack in Kabul March 25, 2015. (Photo by Omar Sobhani/Reuters)