A bomb has blown up a bus in Afghanistan killing at least 11 people and wounding dozens, officials said today, the latest in a series of deadly blasts that has come as foreign forces withdraw.

The roadside bomb exploded late yesterday in the southern province of Zabul, the provincial governor's spokesman said.

Woman and children were among the wounded, he said. An interior ministry spokesman said 28 people were wounded.

There was no immediate claim of responsibility. Taliban insurgents did not immediately respond to a request for comment.

Furthermore, a blast hit a minibus in Parwan province earlier today, just north of the capital Kabul killing two people and wounding nine, the interior ministry said.

Violence has been rising sharply in recent weeks after the United States announced it would withdraw all of its troops by 11 September, 20 years after al Qaeda attacks on the United States triggered US-led intervention in Afghanistan.

The Taliban announced late last night they would declare a three-day ceasefire for the religious holiday of Eid al-Fitr later this week.

The ceasefire declaration came two days after bombings outside a school in Kabul killed 68 people, most of them girl students, and injured more than 165 people.