The bus belonged to the ministry of mines and petroleum, and warned the death toll could change.

At least 10 people -- including several women and a child -- were killed and 41 others wounded by a series of blasts that rocked the Afghan capital Thursday ahead of the election season.

The three blasts came amid a wider surge in violence in Kabul and around Afghanistan, where nine family members were killed in an eastern province Thursday while heading to a wedding.

The Taliban claimed responsibility for one of the Kabul blasts, which came just three days before the official campaign season for the September 28 presidential election gets underway.

Previous polls have been marred by violence and bloodshed from the Taliban and other insurgent groups who refuse to recognise Afghanistan's fragile democracy.

According to interior ministry spokesman Nasrat Rahimi, the first blast came around 8:10 am (0340 GMT) when a suicide bomber riding a motorcycle hit a bus in eastern Kabul. He said the bus belonged to the ministry of mines and petroleum.

A second blast detonated nearby soon after, with a third coming in a separate district also in eastern Kabul, Rahimi added.

Health ministry spokesman Wahidullah Mayar said the toll from the blasts was at least 10 dead, including five women and a child, and 41 wounded.

The attacks come as the US is negotiating for a deal that would see foreign forces pull out of Afghanistan in return for a ceasefire and various Taliban security guarantees, including a pledge that the country will not become a safe haven for terror groups.

Some observers say the insurgents are increasing attacks to gain greater leverage in the talks.

Family killed

The Afghan war continues to take a brutal toll on civilians even amid the push for peace.

Attaullah Khogyani, spokesman for the eastern province of Nangarhar, said a car carrying a family on its way to a wedding was hit by a roadside bomb Thursday in Khogyani district.

As a result, six women and three children were killed, he said. No group immediately claimed responsibility.

A suicide attack on a wedding in Nangarhar on July 12, reportedly by a child bomber, was claimed by the Islamic State group, which has a growing footprint in that part of Afghanistan.

US peace envoy Zalmay Khalilzad, who is in Kabul this week, is expected to travel to Qatar's capital Doha in coming days for the new round of talks with the Taliban.

The US has also stepped up its air campaign against the Taliban this year, and all sides claim to have inflicted heavy casualties on each other.

Still, the US and the Taliban insist they are making progress, and the insurgents and a group of Afghans this month made a vague and unbinding pledge to try to reduce civilian deaths to "zero".

But civilians continue to pay a heavy price in Afghanistan's raging conflict, with last year the deadliest on record for ordinary Afghans.

According to a UN tally, at 3,804 civilians died in the war in 2018, including 927 children.

President Donald Trump has said he wants the US to quit Afghanistan as soon as possible.

He provoked outrage in Afghanistan this week when he claimed he could easily win the war but did not "want to kill 10 million people" or wipe Afghanistan "off the face of the Earth".