KABUL, Afghanistan — Violence spiked in southern Afghanistan as militants stormed a NATO military base and attacked a police checkpoint Tuesday, a day after gunmen wearing police uniforms killed a U.S. soldier.
The heaviest fighting in Afghanistan this summer has been in the south and east where Afghan forces are increasingly taking charge of security from their international partners. That could signal a rocky transition as foreign combat troops are due to withdraw by the end of 2014.
Most of the attacks over the past two days occurred in the southern Kandahar province, the Taliban's birthplace.
Insurgents attacked a NATO base before dawn Tuesday in Kandahar's Shah Wali Kot district, but no service members were killed, the U.S.-led coalition said.
"Initial reports indicate that seven insurgents launched an attack on a NATO installation and initially were successful in breaching the outer security perimeter," NATO said in a statement. "Current reporting indicates all the attackers have been killed."
The Taliban claimed responsibility for the attack, saying it was targeting troop sleeping quarters.
Provincial government spokesman Javid Faisal said initial reporting indicated that at least one foreign worker was killed and two other foreigners were wounded, but the report could not be independently confirmed.
A few hours later, militants wearing Afghan police uniforms attacked a police checkpoint in Kandahar city. Three policemen were killed and nine others were wounded during an hour-long gun battle that ensued, according to the Ministry of Interior. Four militants also died.
The Taliban again claimed responsibility and said the clash lasted six hours.
The U.S. and other foreign troops have increasingly been targeted by Afghan security forces, or militants disguised in their uniforms.
On Monday, three gunmen dressed in Afghan police uniforms killed one American service member and wounded nine others in Kandahar's Zhari district, U.S. officials said, speaking on condition of anonymity because the attack was still under investigation. Faisal, the spokesman for Kandahar province, said the attackers fired a rocket-propelled grenade at the coalition forces and then fled the scene.
The Defense Department said U.S. Army Pfc. Jarrod Lallier, 20, of Spokane, Washington, died after his unit was attacked with small arms fire and grenades. He was assigned to the 1st Battalion, 508th Parachute Infantry Regiment, 4th Brigade Combat Team, 82nd Airborne Division from Fort Bragg, North Carolina.
Efforts to draw down the number of U.S. troops in Afghanistan rely on the Americans working closely with their Afghan partners to train and mentor them so that they can take over the security of their country. Such insider attacks fuel distrust between the two forces and have triggered increased security protections for the U.S. service members serving in Afghanistan.
It remains unclear whether the gunmen were actual members of the Afghan National Police or militants dressed in their uniforms.
The number of insider attacks in the country has escalated, with more than a dozen fatal assaults already this year that have led to more than 20 deaths.
Last year 21 fatal attacks killed 35 coalition service members, according to the coalition. That compares with 11 fatal attacks and 20 deaths the previous year. In 2007 and 2008 there were a combined total of four attacks and four deaths.
The increase accelerated after a series of mistakes and other behavioral problems by U.S. troops serving in Afghanistan, including the burning of Qurans and other religious materials earlier this year at a U.S. base north of Kabul.
Separately, the coalition said a NATO service member was killed Tuesday in an insurgent attack in southern Afghanistan. No other information was released so it was unclear whether the service member died in one of the attacks in Kandahar province or elsewhere in the south. So far this year, 200 NATO service members have been killed in Afghanistan.
In other violence Tuesday, gunmen assassinated two local government employees in the Chaparhar district of Nangarhar province in eastern Afghanistan, said the governor's spokesman, Ahmad Zia Abdulzai. The Taliban routinely target Afghan officials in an attempt to weaken the resolve of a government they say is collaborating with foreign occupiers.
Civilians also continued to be targeted.
A car hit a roadside bomb Monday in the Musa Qala district of southern Helmand province, killing eight civilians, including women and children, the governor's office said in a statement issued on Tuesday.
Meanwhile, Afghan authorities announced that two men have been charged in connection with a Dec. 6 suicide bombing that killed 56 worshippers and wounded more than 160 others last year outside a Shiite shrine in Kabul. It was Afghanistan's first major sectarian assault since the fall of the Taliban regime more than a decade ago.
Officials with the Afghan intelligence service and Attorney General Mohammed Ishaq Aloko told reporters the two men confessed to transporting the suicide attacker from Peshawar, a city in northwest Pakistan, to the shrine in Kabul.
Lashkar-e-Jhangvi, a Pakistan-based group that has carried out other attacks against Shiite Muslims, claimed responsibility for the bombing.
The attorney general said the bombing was an attempt to create division between Afghan Sunni and Shiite Muslims. He alleged that the Pakistani intelligence service was involved in the attack during the period of Ashoura, which marks the seventh century death of Imam Hussein, a grandson of the Prophet Muhammad.
Pakistan has repeatedly denied Afghan officials' allegations that it facilitates attacks in Afghanistan.
One of the men, Rahim Gul from Bati Kot district of Nangarhar province, told officials on a taped confession that he transported the suicide bomber because he was poor and badly needed the 10,000 Pakistani rupees (about $106) the organizers of the plot had agreed to pay him. The second man charged, Habibullah, who uses only one name, is from Nangarhar's Surkh Rod district.
Associated Press writers Mirwais Khan in Kandahar and Rahim Faiez and Amir Shah in Kabul contributed to this report.