Suicide blast in Afghanistan kills at least 68

A suicide bomber in Afghanistan killed at least 68 people and wounded more than 100 others at a demonstration on Tuesday on the highway between the eastern city of Jalalabad and the main border crossing into neighbouring Pakistan, officials said.

Officials and elders said Tuesday's attack targeted a gathering to protest against a police commander, adding that hundreds of people were present when the blast happened.

The blast dispersed the crowd, but more people gathered after the explosion to continue the protest. The details of the complaint against the police chief were not immediately clear.

The blast, less than a week after a suicide attack killed more than 20 people in the capital, Kabul, came as violence has flared across the nation, with heavy fighting in northern provinces.

Officials have warned violence is likely to intensify ahead of parliamentary elections next month and a presidential election in April.

There was no immediate claim of responsibility for Tuesday's attack. The Taliban issued a statement denying involvement.

Attaullah Khogyani, spokesman for the governor of Nangarhar, said 32 people were dead and 128 were wounded in the blast.

Local officials said bodies and wounded men were rushed to private and government hospitals.

Journalist Ali Latifi has the latest from the capital Kabul.

Another official Sohrab Qaderi, a member of the Nangarhar provincial council, said at least 56 bodies were taken to hospital, with 43 more wounded. That higher death toll was not confirmed.

Qaderi said rescue efforts were being hampered by reports of another suicide bomber in the area, making police and emergency services cautious about approaching the scene.

The escalating violence has dampened hopes of peace talks to end Afghanistan's 17-year conflict but two Taliban officials on Tuesday told Reuters the movement was preparing for another meeting with US officials following one in July.

Nangarhar, one of the main strongholds of Daesh terror group since early 2015, has been one of the most volatile regions this year, with a string of suicide bombings and attacks on its capital, Jalalabad.

The explosion at the protest followed a series of smaller blasts on Tuesday that targeted schools in Jalalabad and surrounding districts, killing at least one person and wounding three.

In the northern province of Sar-e Pul, hundreds of armed men assembled to boost the city's defences as security forces fought to push the Taliban back from the city centre, said Zabihullah Amani, the provincial governor's spokesman.

There were no reports of US strikes in Sar-e Pul on Tuesday but there were three strikes on Monday, a spokesman for US forces in Afghanistan said in an emailed statement.

Two air strikes in Baghlan province on Tuesday followed six the day before and American advisers were on the ground supporting Afghan troops, the spokesman added.

Ghulam Mohammad Balkhi, deputy spokesman for the Afghan army's 209 Corps, said at least 30 Taliban fighters were killed in the joint operation.