Taliban suicide bombers have killed at least 48 people and wounded dozens more in two bomb blasts in Afghanistan.

It comes as insurgents have warned of more violence ahead of elections.

The first attack saw a motorcyclist detonate a suicide bomb at a checkpoint leading to a rally where President Ashraf Ghani was addressing supporters in central Parwan province, just north of the capital, killing 26 and wounding 42.

Just over an hour later, another blast also claimed by the Taliban rocked central Kabul near the US embassy.

Authorities initially did not give casualty figures, but later said 22 people had been killed and a further 38 wounded.

An AFP image from the scene near President Ghani's rally, north of Kabul, showed the remains of a burnt motorcycle, with a body on top, covered by a blanket next to a badly damaged police car.

Women and children were among the casualties, Parwan hospital director Abdul Qasim Sangin told AFP.

The explosions came after US President Donald Trump abruptly ended talks with the Taliban earlier this month over a deal that would have allowed the US to begin withdrawing troops from its longest war.

In a statement sent to media claiming responsibility for both blasts, Taliban spokesman Zabihullah Mujahid said the attack near President Ghani's rally was deliberately aimed at disrupting the 28 September elections.

"We already warned people not to attend election rallies, if they suffer any losses that is their own responsibility," the statement said.

Meanwhile, a BBC investigation released on Monday claimed that 74 people were killed every day on average in Afghanistan in August, with 611 incidents resulting in 2,307 deaths.

The president, who was speaking to his supporters at the time of the blast, was unhurt but later condemned the attack, saying the incident proved the Taliban had no real interest in reconciliation.

"As the Taliban continue their crimes, they once again prove that they are not interested in peace and stability in Afghanistan," the president said in a statement.

The UN's mission in Afghanistan also slammed the Taliban, accusing them of showing "despicable disregard for civilian life and the fundamental human right to participate in democratic process".

The elections will see President Ghani face off against his own Chief Executive, Abdullah Abdullah, and more than a dozen other candidates, including former warlords, ex-spies, and one-time members of the country's former communist regime.

Afghan President Ashraf Ghani

For weeks, the election had been sidelined by the US-Taliban talks, with many Afghans and observers expecting the vote to be cancelled if a deal was agreed. Even candidates did little in the way of campaigning.

But with the deal off, President Ghani and his rivals have begun the race.

Mr Ghani is seeking a clear mandate that they can use to negotiate with the insurgents on a lasting peace in Afghanistan.

President Trump's declaration that the US-Taliban talks were "dead" spurred the insurgents to declare last week that the only other option was more fighting.

On the first day of campaigning in July, suicide attackers and gunmen targeted the Kabul office of President Ghani's running mate, Amrullah Saleh.

At least 20 people died in those attacks.

Turnout in the elections is set to be low, with experts citing fear of violence and a loss of hope among voters following widespread fraud allegations during the 2014 election.