No injuries were reported from the mortar rounds that hit in the diplomatic quarter; one struck near the presidential palace, another near a NATO compound and the U.S. Embassy, according to police official Jan Agha.
In response, Afghan helicopter gunships bombed the house from which the rockets were believed to have been launched. Hours later, at least two militants were reported killed. The booms of the mortar rounds echoed during the live broadcast of Ghani's speech commemorating the Eid al-Adha holiday, and the president interrupted his remarks to say: "If they are thinking the rocket attack will keep Afghans down, they are wrong."
The attack came amid an unrelenting wave of deadly violence across the country in recent weeks and dealt another blow to Ghani's efforts to revive peace talks to end the 17-year war. On Sunday, he had offered a holiday cease-fire, saying it would only take effect if the Taliban reciprocated.
An affiliate of the Islamic State group claimed responsibility, saying its fighters had fired the shells that struck the heavily fortified Kabul neighborhood. There was no immediate comment from the Taliban.
The Interior Ministry launched an investigation into the security breach. Former Interior Minister Noorul Haq Olomi blamed political squabbling inside Ghani's government for distracting the president's attention from security matters, allowing the near-daily violence by insurgents to continue.
"The deaths every day of our security forces is a big calamity for our country," said Olomi, now a defense analyst. He also blamed neighboring Pakistan, saying that the international community has done too little to force Islamabad to shut down safe havens for terrorist groups inside its territory. The U.S. and Afghanistan also have routinely alleged that Pakistan harbors Taliban insurgents,
Pakistan denies the allegation and says some of the deadliest terrorist attacks on its territory have been plotted by the Islamic State affiliate based in Nangarhar province in eastern Afghanistan. Afghan security forces, aided by U.S. air support, have repeatedly struck IS redoubts in Nangarhar in recent months with some success, although the group still has been able to carry out attacks. Last week, it claimed responsibility for a suicide bombing that killed 34 high school graduates, most of them Shiites, who were taking university entrance exams in Kabul. The IS affiliate is known as the Islamic State in Khorasan Province, the ancient name of an area that once spanned parts of Iran, Afghanistan and Central Asia.
In Islamabad, new Prime Minister Imran Khan condemned the rocket attack. "We are with the Afghan people and government to fully defeat this cowardly thinking," Khan said in an Urdu language statement.
The Kabul neighborhood where the mortar rounds hit is one of the most secure in the capital, where embassies and government buildings are surrounded by concrete blast walls and coils of razor wire. Many streets near the U.S. Embassy are closed off, along with those near sensitive government and military installations.
"It is clear that those that carried out the attack are enemies of Afghanistan, enemies of Islam and enemies of peace," said Lt. Col. Martin O'Donnell, a spokesman for U.S. forces in Afghanistan. Police had noticed a suspicious vehicle and followed it to a mud-brick house near the sprawling Eid Gah mosque, where hundreds were praying during the Eid al-Adha holiday, said police spokesman Hashmat Stanekzai. He told The Associated Press that the militants were believed to have fired the rockets from the house.
A helicopter gunship bombed the location, destroying the house and the vehicle. After the explosions, witnesses reported sporadic shooting could be heard from the area, though it wasn't clear who was firing. The witnesses spoke on condition of anonymity, fearing for their safety.
O'Donnell said four attackers were killed and five surrendered. But Interior Ministry spokesman Najib Danish said two attackers were killed. Danish initially said that two Afghan security forces were wounded in a subsequent firefight, but later revised the number to six, including some civilians. The gunbattle also ignited a fire that burned down a nearby market, he said.
The U.N. special representative to Afghanistan, Tadamichi Yamamoto, pleaded for peace on the Muslim holiday. "To allow all Afghans to commemorate this auspicious celebration, I strongly urge the parties to the conflict to demonstrate good will, to respect this time of joy and tolerance and to refrain from resorting to violence," he said.
On Monday, the Taliban ambushed a convoy of buses and abducted scores of people, including women and children. Afghan forces rescued nearly 150 of them. Earlier this month, the insurgents launched a coordinated assault on Ghazni, a strategic provincial capital only 120 kilometers (75 miles) from Kabul. It took Afghan forces, aided by U.S. airstrikes and advisers, more than five days to drive them out in a battle that killed at least 100 security forces and 35 civilians, while about 200 militants were killed.
Both the Taliban and the Islamic State group are fighting to overthrow the U.S.-backed government and impose a strict form of Islamic rule. But they are fiercely divided on leadership, tactics and ideology, and routinely clash with one another.
The U.S. and NATO officially ended their combat mission at the end of 2014 but have repeatedly come to the aid of Afghan forces in recent years to prevent the Taliban from advancing into major cities. The U.S. has long insisted on an "Afghan-led" peace process between the government and the Taliban but recently has indicated it would be open to direct talks with the insurgents.
The Taliban have sent delegations to Uzbekistan and Indonesia in recent weeks. On Tuesday, Russia's foreign minister Sergey Lavrov said the Taliban have accepted an invitation to attend talks on Afghanistan in Moscow on Sept. 4.
All this has raised the Taliban's diplomatic profile while carrying out the deadly attacks. The Taliban say they met with a U.S. diplomat in Qatar this month for what the group described as "preliminary" talks, and said it expected further negotiations.
Gannon reported from Islamabad. Associated Press photographer Rahmat Gul in Kabul, correspondent Munir Ahmed in Islamabad, Vladimir Isachenkov in Moscow and Maamoun Youssef in Cairo contributed.