A suicide attack at a wrestling club in a Shi'ite neighbourhood of the Afghan capital Kabul and a second explosion apparently targeting emergency services and journalists have killed at least 20 people and wounded 70, officials say.

There was no immediate claim of responsibility for the attack on Wednesday night in Dasht-e-Barchi, home to many members of the mainly Shi'ite Muslim Hazara ethnic minority which has been targeted in the past by Sunni militants of Islamic State.

Last month, dozens of students preparing for a university entrance examination were killed at an educational centre in the area.

Kabul police spokesman Hashmat Stanekzai said the second explosion hit as police were helping victims and a number of journalists were at the site.

Pictures showed young men in torn wrestling kit helping the wounded onto vehicles to be taken to hospital.

A reporter and a cameraman from Afghanistan's largest broadcaster, Tolo News, were killed in the second blast and four other local television crew were wounded, according to NAI, a group supporting open media in Afghanistan.

Wednesday's attack underlined the danger in Kabul as elections approach next month, as well as the threat facing the Hazaras, a Persian-speaking minority that has long faced discrimination and which has borne the brunt of attacks claimed by Islamic State in Kabul.

The explosion came as Secretary of State Mike Pompeo announced that Washington's former ambassador to Afghanistan, Zalmay Khalizad, would be appointed as an adviser to help with efforts to end the conflict.

Hopes of possible peace talks with the Taliban were fuelled by a brief ceasefire in June, although intense fighting in the months since has dampened optimism.

In any case, any talks would not include the local affiliate of Islamic State, which has established a brutal reputation and which both the Western-backed government and the Taliban consider an enemy.

Courtesy: 9 News