At least four rounds of indirect fire hit or struck near Bagram Airfield on Thursday night, with one round hitting the detention facility on base.
As of Friday morning, officials said no injuries were reported on base and that “all personnel and detainees in the facility are safely accounted for.”
The U.S. military said it was not known if any civilians living near the base had been hurt in the attack, the second against the base in a week.
On Wednesday, an attacker set off a car bomb and a suicide vest device near a base gate. Only the bomber was killed, though three contractors were injured in that incident.
The attacks against the base highlight the security concerns that have stretched even to Afghanistan’s capital, Kabul. Though the Taliban and other insurgent groups are strongest in the south and east of Afghanistan, the fighting has spread throughout the country.
In early February, a coordinated assault by Taliban gunmen and bombers killed at least 20 people in Kabul, a demonstration that insurgents have been able to pierce the capital’s relative calm.
Bagram is about 40 miles from Kabul. About 10,000 international troops are stationed at Bagram, a former Soviet base.
A public opinion survey released in late February underscored plummeting public confidence in Afghanistan. Just 40 percent of those surveyed said they felt the country was heading in the right direction, down from 77 percent in 2005. Only 32 percent of Afghans said the U.S. was doing a good job in the country, compared with 68 percent three years ago, according to the poll.
The poll, conducted by ABC News, the British Broadcasting Corp. and ARD German TV, also showed falling support for the government of Afghan President Hamid Karzai. In 2005, 80 percent of Afghans said they supported the Karzai regime, but just 49 percent say the same thing now.
According to a study released in December by an influential British think tank, three of the four major routes leading to Kabul have been “compromised” by the Taliban, “closing a noose around the city and establishing bases close to the city from which to launch attacks inside it.”
The report, by the International Council on Security and Development, charted a dramatic rise in Kabul attacks, including kidnappings of Afghans and foreigners; bomb attacks and assassinations.
President Barack Obama has ordered an additional 17,000 U.S. troops to Afghanistan this year, and the administration is conducting reviews of its war strategy.