A loud explosion has rocked the centre of Kabul, hours after a Taliban suicide attack near the Defence Ministry killed at least 24 people, including a number of senior security officials, and wounded 91 others, officials say.
Sporadic gunfire could be heard in an area of the city near to embassies and government buildings, including the Interior Ministry but there was no immediate claim of responsibility and no word on any casualties.
Earlier, twin blasts in quick succession tore through an afternoon crowd in a bustling area of the city close to the Defence Ministry.
The Taliban immediately claimed responsibility for that attack, in which a suicide bomber caught security forces personnel and civilians who rushed to help victims of the first explosion.
"When the first explosion happened people crowded to the site and then the second blast occurred, which was really powerful and killed lots of people," said Samiullah Safi, who witnessed the attack.
An army general and two senior police commanders were among the dead, a Defence Ministry official said.
The Taliban claimed responsibility for the attack, which it said killed 58 officers and commanders.
The militants have stepped up their campaign against the Western-backed government in recent weeks, following a brief lull after the death of their former leader, Mullah Akhtar Mansour.
The double bombing came less than two weeks after gunmen attacked the American University in Kabul, killing 13 people.
It was the deadliest attack in Kabul since at least 80 people were killed by a suicide bomber who targeted a demonstration on July 23. That assault was claimed by Islamic State.
Government officials have been preparing for a conference in Brussels next month at which foreign donors, concerned about the ability of the Afghan security forces to withstand Taliban violence, are expected to pledge continuing support over coming years.