A Nato helicopter has crashed in southern Afghanistan, killing six members of the international military force, the US-led coalition said Friday.
The cause is still being investigated, but a coalition statement said there was no enemy activity in the area at the time of Thursday's crash, which brought the number of international forces killed in Afghanistan this month to 24.
The coalition did not disclose the nationalities of those killed and would not release details of the crash until the families of the dead were notified.
The helicopter crash occurred on the same day that a suicide car bomber killed at least seven civilians outside a crowded gate at Kandahar Air Field, a sprawling base for US and Nato operations in the south. The Taliban insurgents claimed responsibility, saying they were targeting a Nato convoy.
It was the second suicide bombing in as many days in southern Afghanistan, officials said. The coalition said no Nato troops were killed Thursday. It does not disclose information about wounded troops.
The Taliban have been stepping up attacks in southern Afghanistan, the birthplace of the insurgency, with a wave of bombings and the assassinations of three local Afghan officials this week. The violence comes even as the US is moving ahead with plans for negotiating with the Taliban to try to end the 10-year-old war in Afghanistan.
Two witnesses told The Associated Press that they suspect Thursday's suicide car bomber was trying to hit US troops because he detonated his explosives just as two pickup trucks, which they say are often used by American special forces, were leaving the base.
Taliban spokesman Qari Yousef said that Nato forces opened fire after the bombing and that they killed three of the seven civilians who died. The coalition denied this, saying there was no fighting after the blast.
Earlier, officials reported that the suicide bomber was walking near the gate, but the Afghan Ministry of Interior later said the attacker was driving a Toyota Corolla.
Zalmai Ayubi, the spokesman for the Kandahar provincial governor, said two children were among the seven civilians killed. He said eight other civilians, including two children and one woman, were injured in the explosion.
Gates to the larger US bases in Afghanistan often are crowded with trucks waiting to deliver goods and services, and local Afghans going to or coming back from jobs on the compounds.
Safiullah, a 40-year-old fuel tank driver from neighboring Zabul province, was waiting his turn to enter the base when the blast occurred.
``There was dust and smoke everywhere,'' said Safiullah, who uses just one name. ``I got down on my knees. When the smoke lifted, I moved closer. I saw two children dead at the side of the road.''
At the time of the explosion, two pickup trucks were leaving the base, he said. He said he remembered that, because he and another man were conversing at the time about how US special forces sometimes use that kind of truck.
The explosion shattered the window of a taxi driven by Sabiullah Khan, who was at the gate waiting for customers.
``I put my head down in my car,'' he said. ``For three or four minutes I was afraid. I was reciting the words of the Quran,'' the Muslim holy book. ``When the smoke cleared and I knew I was OK, I started looking outside. People were shouting for help. I saw one vehicle on fire. The Afghan army were running and taking out the wounded.''
He said that when he got out of his taxi, he also saw the two pickup trucks.
``Nobody was in them, but from the condition of the vehicle, I'm sure that if they were not killed, they were wounded,'' he said.
On Wednesday, 13 civilians, including three Afghan policemen, were killed when a suicide attacker blew himself up in a bazaar in neighboring Helmand province.
The Helmand governor's office said 22 others were wounded in the blast in Kajaki district.
The coalition said some international troops were killed and wounded in the attack, but did not disclose details.
Late Wednesday, Nato reported that one coalition trooper had been killed in an explosion in southern Afghanistan, but would not say whether the service member died in the Kajaki bombing, or some other incident.
US Gen. John Allen, the top commander of American and Nato forces in Afghanistan, condemned the Kajaki attack, saying it was evidence that the Taliban insurgents had ``declared outright war'' on the Afghan people. He said that such violence ``will only further isolate the Taliban from the process of peace negotiation.''
The US has been working to broker talks between the Taliban and President Hamid Karzai's government to end the 10-year war. The insurgents recently said they would open a political office in the Gulf state of Qatar to pursue negotiations but would also continue fighting.
Several current and former US officials said the most substantive give-and-take to date between US and Taliban negotiators could happen in the next week, with the goal of establishing what the US calls confidence-building measures _ specific steps that both sides agree to take ahead of formal talks.
However, US intelligence agencies recently offered a gloomy prognosis in their latest Afghanistan report.
The Afghan National Intelligence Estimate warns that the Taliban will grow stronger, using the talks to gain credibility and run out the clock until US troops leave Afghanistan, while continuing to fight for more territory, say US officials who have read the classified document. They spoke on condition of anonymity to describe the roughly 100-page review, an amalgam of the intelligence community's predictions of possible scenarios for the Afghan war through the planned end to US combat in 2014.
The report says the Afghan government has largely failed to prove itself to its people and will likely continue to weaken and find influence only in the cities. It predicts that the Taliban and warlords will largely control the countryside.