KABUL, Afghanistan — More than 10,000 people gathered Thursday in Kabul to oppose reconciliation with the Taliban and the involvement of Pakistan in any peace deal, warning that it would be a betrayal of the Afghan people’s long fight against extremism.

The meeting, organized by a former intelligence director, Amrullah Saleh, and attended as well by Abdullah Abdullah, a former presidential candidate, was a frontal attack on the current government’s policies, and speakers denounced both Al Qaeda and the Taliban. The organizers promised that if they were not listened to, they would “go to the streets and protest.”

Under the name “a gathering for justice,” the meeting was attended overwhelmingly by Afghans from the north and particularly from Panjshir Province, the home of the Afghan icon Ahmed Shah Massoud, who was killed by suicide bombers backed by Al Qaeda two days before the Sept. 11, 2001, attacks. Panjshir is also the home province of Mr. Saleh and Mr. Abdullah.

Both men have long experienced friction with President Hamid Karzai: Mr. Karzai forced out Mr. Saleh, and Mr. Abdullah withdrew from a runoff election against Mr. Karzai in 2009 because, he said, the voting would be rigged. “The Taliban and Al Qaeda are terrorists,” said Mr. Saleh, as he looked out across the crowd, many of them young people. “They have destroyed our lands and houses, dishonored our wives and families.”