At least seven people lost their lives while 21 others sustained injuries, officials said earlier.
At least 12 people were killed as three bombs rocked the Afghanistan capital of Kabul on Thursday.
The first blast went off in a bus carrying government employees, killing a total of at least 12 people, news agency Reuters reported quoting officials.
Five employees of the ministry of mines and petroleum were killed and 10 wounded in the bus attack, the officials said, adding that seven people were killed and 21 wounded in the second explosion.
"First a magnetic bomb pasted to a minibus exploded, then a suicide bomber blew himself near the bus attack site and the third blast happened when a car was blown up by unknown militants," said Nasrat Rahimi, a spokesman of the interior ministry in Kabul.
"The death toll could rise from all the three blasts," he said.
No militant group has claimed responsibility for the attacks.
The United States is trying to negotiate a deal that would see foreign forces pull out of Afghanistan. The eighth round of talks is expected to begin this month in Qatar.