An explosion rocked east of Afghan capital Kabul on Sunday, leaving two people dead and 20 others injured, all civilians," deputy to Kabul police chief Syed Abdul Ghafar Syedzada said.

"School children were also among the injured in the blast," Syedzada told journalists at the site of the incident, without revealing further details.

Earlier, an official, on condition of anonymity, had told Xinhua that the incident, which took place at 11:55 a.m., was a suicide motorbike attack against NATO-led troops. He said two NATO soldiers were injured and the suicide bomber was killed in the blast.

The latest blast took place amid tight security as the Afghan government will host an international conference on the war-torn nation on Tuesday.

Some 16,000 security forces have been tasked to ensure security for the conference, which will be attended by representatives from more than 70 countries and international organizations, including over 30 foreign ministers.

Personnel of security agencies have already been deployed on entry points to Kabul city and sensitive areas and buildings