Official sources said, the meeting was about to be addressed by President Ashraf Ghani in Parwan province, north of the capital, Kabul.
Mr Ghani’s campaign chief said, the President was present at the venue but was unharmed.
Just hours later, an explosion struck near the U.S. Embassy in Kabul with reports of three people killed.
No group immediately claimed responsibility for the attacks.
The violence comes as Afghanistan faces presidential elections on September 28.
The Taliban has warned that polling stations and election campaigns would be targeted.
Campaigning for the Afghan elections resumed last week after US President, Donald Trump declared that the US – Taliban talks which had been going for months in the Gulf Arab state of Qatar, are over.