An explosion swept through a mosque in the Afghan city of Kabul during evening prayers on Wednesday, according to a hospital-operating NGO. At least three people were killed, and scores more were injured.

"Following today’s explosion, we admitted 27 patients to our Surgical Centre for War Victims in Kabul, including five minors, one of them a 7-year-old boy," said Stefano Sozza, Afghanistan head of the Italian NGO Emergency. "Two patients arrived dead, one died in the Emergency Room."

The death toll could be significantly higher. A security officer told Al Jazeera that the blast claimed the lives of twenty individuals.

Zabihullah Mujahid, a Taliban government spokesperson, tweeted that the explosion occurred in the Khair Khana neighborhood, which is located in northwest Kabul.

There was no immediate claim of responsibility for the blast, but ISIS has increased its operations against the Taliban over the past year.

The head of U.S. Central Command, Gen. Kenneth McKenzie, issued a warning earlier this year that additional ISIS strikes may be expected in the summer.

"We’re coming out of the winter; traditionally this would now begin the fighting season," McKenzie told the Senate in March. "It is my expectation that ISIS attacks will ramp up in Afghanistan as we go into the summer."