Gunmen are still at large in many areas
A day of explosions and fighting across Afghanistan has left at least 57 people dead.
Officials quoted by Reuters news agency said it had been the bloodiest 24 hours in more than a year.
An explosion in a minibus in the southern province of Helmand killed 15 people, including six children and a woman, whilst a blast in a house in the capital, Kabul, left two students dead.
Afghan troops battled militants in Khost Province near the border with Pakistan and rival tribesmen clashed in Uruzgan Province.
Fifteen suspected Taleban fighters and five Afghan soldiers died in the Khost fighting after troops were attacked overnight in a traditional Taleban stronghold.
Government reinforcements forced the militants back, an army commander said.
In Uruzgan, about 20 people died as supporters of Amanullah, a former ruler of the remote district of Kajran, clashed with forces loyal to his
successor, Abdul Rahman Khan.
The bus blast happened 30 kilometres (20 miles) from Helmand's provincial capital, Lashkar Gah, in the Nadi Ali district.
Officials say the bus explosion was probably caused when a bomb being carried by one of the passengers blew up prematurely.
They are blaming former Taleban members for the incident.
The administrative chief of Helmand Province, Ghulam Mahaiuddin, told reporters the bomb may have been intended to disrupt Afghan independence celebrations, which are due to take place in Lashkar Gah next week.
"They are killing innocent people," said Mr Mahaiuddin.
Helmand Province has suffered an increase in violent attacks recently, which have been blamed on resurgent Taleban and al-Qaeda fighters operating out of Pakistan.
In Kabul, two students were killed and another injured in an explosion in a house in the western part of the city.
Police say the students were Taleban or al-Qaeda sympathisers who were planning to attack targets in the capital.
The latest incidents came two days after Nato took command of international peacekeepers charged with maintaining security in Kabul.
Afghan Government and UN officials have been urging the peacekeepers to extend their patrols to the countryside outside Kabul, where rising crime and militancy have set back reconstruction efforts.