At least 29 people have been killed and 52 others wounded in a mid-day explosion in the Afghan capital, Kabul.
The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group claimed responsibility for Wednesday's attack, which took place close to Kabul University and Ali Abad hospital, its Amaq news agency said.
News reports quoted the interior ministry as saying that a suicide bomber had detonated his explosives while walking among a group of people.
The attack happened as many Afghans are marking the Nowruz holiday, a celebration of the start of spring and the Persian new year.
Last Tuesday, on the eve of Nowruz, interior ministry officials had said that there was enough security for the celebration.
In an interview with Al Jazeera from Kabul, Habib Wardak, a national security analyst, said the timing and location of the attack was "no coincidence".
"It's a national holiday for us. A lot of people are gathering across various points in the city, and this is certainly one of them where people celebrate the new year."
He said there is a shrine in the area popular among Afghans celebrating the Persian new year.
Wardak said there was a "glimmer of hope" that the new year would bring new effort for reconciliation. But he said the latest explosion is "not a good sign".
Since the beginning of this year, ISIL and the Taliban have launched a series of deadly attacks across the country, killing more than 200 people in Kabul alone, according to an Al Jazeera tally.
On Saturday, a Taliban suicide bomber detonated explosives near a compound for foreign security contractors in Kabul, killing three civilians.
Amid the deteriorating security situation, General John W Nicholson Jr of the US Army said in December that his country would deploy more troops in an advisory role to Afghan forces in 2018, on top of the 14,000 American soldiers already stationed in the country.
The US invaded Afghanistan in 2001 to topple the Taliban. Since then thousands of civilians have been killed in the bloody fighting between the US-backed Afghan government forces and the armed group.