At least 15 people were killed and 45 others wounded as an explosion rocked a provincial governor's office after a meeting between Afghan officials and Taliban members here on Sunday, a security official said."The initial information found a terrorist blew his explosive jacket up at the gate of the building roughly at 3.15 p.m. local time when people were leaving the building when the meeting ended," a security source told Xinhua news agency.The death toll was likely to go up as many of the injured were in critical condition, the source added.The government announced a seven-day ceasefire from June 12 to encourage the Taliban to support the national reconciliation process.Reciprocating the step, the armed group announced a three-day truce from the first day of Eid-ul-Fitr, Friday, to the end of Sunday.Provincial Governor's spokesman Attahullah Khogyani confirmed the incident to Xinhua.He said a probe was on and information about the identity of the victims would be shared with media later in the day.On Saturday, 25 people were killed and 54 others wounded in another similar incident on the outskirts of Jalalabad, capital of Afghanistan's eastern Nangarhar province, for which the Islamic State militants claimed responsibility.Afghan President Ashraf Ghani on Saturday extended the ceasefire for an unknown period of time.