At least 102 people were killed and nearly 200 others injured on Saturday when a Taliban suicide bomber exploded an ambulance laden with explosives near Sidarat Square in central Kabul where several government offices are located.
"At least 102 people killed, 196 others wounded. We fear the number of people killed may go up," health and interior ministry sources told the local media.
The blast took place near Indian embassy in the Afghan capital.
Thick, dark smoke could be seen rising from the site of the Saturday explosion near the old Interior Ministry building.
Taliban has claimed responsibility for the deadly attack, as per Afghan media.
The blast occurred at roughly 12.50 p.m. in front of Jamhoriat Hospital, where several government offices are located, eyewitness Mohammad Mustafa told Xinhua.
"We heard a huge blast in the area which is a few metres away from Sidarat Square. The whole place has now been sealed off," he said.
Security forces have cordoned off the area as a precautionary measure.
Expressing solidarity with Afghanistan, India's Ministry of External Affairs condemned the "barbaric" terrorist attack in Kabul.
"India stands in solidarity with Government & people of Afghanistan at this difficult time of mindless violence & terror imposed on them. We convey our heartfelt condolences to next of kins of victims of these terror attacks & pray for speedy recovery to those injured," MEA said in a statement.
India called for bringing the perpetrators to justice, while offering all possible assistance, including treatment of those injured in the attack.
Taking to Twitter, President Ram Nath Kovind too offered his condolences, reiterating India's resolve of standing "shoulder-to-shoulder with the people and Govt of Afghanistan in the fight against forces of terror".
Meanwhile, Jammu and Kashmir Chief Minister Mehbooba Mufti has also condemned the attack and called upon people to "unite to vanquish nexus of terror"
Kabul has been the site of numerous bombing attacks claimed by the Islamic State group and the Taliban over the last year.
This comes after a deadly attack on the Intercontinental Hotel in the city that killed 22 people, including 4 Americans.