Kandahar, Afghanistan ? Ten Afghan police were reported killed in a suspected Taliban ambush Tuesday as Afghanistan marked its Independence Day in the shadow of renewed violence.

The 10 men died when their vehicle came under fire from about a dozen suspected Taliban assailants in Logar province south of Kabul, according to province officials.

It was the third such attack in three days and pointed to the growing seriousness of an insurgency that has claimed at least 70 lives in the past week.

On Saturday night, up to 200 suspected Taliban fighters attacked the remote region of Birmal in Paktika, and on Sunday night, a second border outpost nearby came under attack. Nine Afghans were reported killed and four captured in those two attacks.

The reports of the numbers of alleged Taliban assailants likely are exaggerated by local officials, but there seems to be no doubt about the increasing reach of the guerrilla insurgency that has revived fears of a Taliban renewal.

Afghan government officials blame Pakistan for permitting Taliban fighters who fled the U.S. onslaught against them in 2001 to launch raids from Pakistan. But the latest ambush took the guerrilla war to within 55 miles of Kabul, far from the Pakistan border, suggesting the insurgents are able to move freely around large swaths of the country.

“The Taliban are there, and they’re crossing the border; there’s no doubt about it,” said Khalid Pashtun, spokesman for the provincial government in Kandahar, where much of the recent Taliban activity has been focused.

The government was convinced, he said, that Pakistan was providing direct support to the Taliban’s efforts to destabilize Afghanistan.

“Every night, the neighboring country’s officials have meetings with the Taliban,” he said. “They are providing absolutely full support.”

Pakistani officials strenuously deny they are aiding Taliban remnants.

Amid fears of terrorist attacks, security was tight at Afghan Independence Day celebrations in Kabul, where President Hamid Karzai watched a parade of schoolchildren as helicopters from the NATO peacekeeping force hovered overhead.

In Kandahar, the occasion was marked with a loud display of music and dancing until early Tuesday.