A U.N. statement said Annan urges all concerned parties in Afghanistan to work in a spirit of national unity and reconciliation. On Monday, at least 20 people were killed and around 20 others injured when an attacker riding a motorcycle detonated explosives
among a crowd at a wrestling match in Spin Boldak, in southern Kandahar province near Pakistan.

Earlier, three Afghan soldiers and at least one other person were reported killed in a blast targeting an Afghan army vehicle in Kandahar city. The Reuters news agency quoted a Taliban spokesman as claiming responsibility for both attacks.

Monday's assaults came after a Canadian diplomat and two Afghans were killed in a Taliban suicide attack Sunday in Kandahar.