A suicide bomber killed 12 policemen in the southern Afghan province of Uruzgan on Friday when he blew himself up inside a police station as officers ate lunch in a dining hall, officials said.
The bomber targeted a base used to patrol the main road from Uruzgan province to neighbouring Kandahar, through one of Afghanistan's most volatile regions where Taliban militants have a strong presence.
"A suicide bomber detonated his explosives in a battalion station in Tirin Kot, the provincial capital of Uruzgan," Abdullah Hemat, the Uruzgan governor's spokesman, told AFP.
"The bomber, who was on foot and wearing a suicide vest, blew himself up while the policemen were having lunch. As a result, 12 policemen were killed and five others wounded," he said.
The attack was the second suicide strike in Afghanistan on Friday after another bomber detonated himself at a border crossing with Pakistan, killing two people including a senior Afghan police commander.
"A suicide bomber wearing a vest of explosives crossed the border into Kandahar's Spin Boldak district this morning and blew himself up," Javed Faisal, spokesman for the Kandahar governor, told AFP.
"A top border police commander and a civilian were killed, and eight others, including two border police and civilians were wounded."
The Spin Boldak-Chaman border crossing is a key route from the Pakistani city of Quetta, which gives its name to the Quetta shura Taliban council, and Kandahar, the insurgency's heartland in southern Afghanistan.
Afghan officials say many suicide attackers who strike in Afghanistan are trained in Pakistan, where the Taliban have rear bases and where some of its leaders are based.
Islamabad denies allowing the Afghan Taliban to operate from inside Pakistan and says it will do everything asked to facilitate Afghan attempts to broker a peace deal to end 12 years of war.
In recent weeks, Taliban insurgents have accelerated their campaign of suicide attacks and roadside bombs against Afghan officials and Afghan and US-led NATO troops.
Last week, the ministry of interior said that 300 police officers were killed in the last month, as Afghan security forces increasingly take on frontline duties fighting the Taliban.
On Monday, a Taliban suicide attack killed nine people in Kabul including four Nepalese, one Briton and a Romanian.
Around 100,000 NATO troops based in Afghanistan are handing over security responsibility to Afghan forces before the international combat mission ends next year.
A Taliban office that opened in the Gulf state of Qatar on June 18 to start peace talks enraged Afghan President Hamid Karzai by styling itself as an unofficial embassy for a government-in-exile.
Karzai broke off bilateral security talks with the Americans and threatened to boycott any peace process altogether.
The Taliban have consistently refused to hold peace talks with the Afghan government and label Karzai as a US puppet.