Allauddin Khan, Associated Press
Afghan soldier mans a checkpoint in Arghandab district, which is partly controlled by Taliban militants, in Kandahar province, Afghanistan, Wednesday.

ARGHANDAB, Afghanistan — Backed by helicopters firing missiles, hundreds of NATO and Afghan forces hunted Taliban militants in villages outside Kandahar on Wednesday, killing dozens of insurgents.

NATO reported only light resistance in Arghandab district, a lush river valley filled with fruit groves that offer militants bountiful defensive positions. The Afghan army says up to 400 militants poured into the area on Monday, just 10 miles northwest of Kandahar city, the Taliban's former power base.

U.S. and NATO officials have repeatedly played down the scope of the Taliban push. But the swift military response — 700 Afghan soldiers flew to Kandahar on a moment's notice — and the fighter aircraft dedicated by NATO suggest that keeping Arghandab free from militants is an urgent priority.

Arghandab is considered a gateway to Kandahar. If militants can gain a foothold there, attacks become easier on the city once commanded by fugitive Taliban leader Mullah Omar.

Elsewhere in Afghanistan, militants killed six NATO soldiers and wounded 10. Just last week Defense Secretary Robert Gates called attention to the worsening situation in Afghanistan, noting that American and allied combat deaths here in May surpassed the monthly toll in Iraq for the first time.

The Afghan Defense Ministry said more than 20 Taliban fighters were killed Wednesday in NATO airstrikes in the Arghandab village of Tabin and 16 more were killed in the village of Khohak. Two Afghan soldiers were also killed, the ministry said in a statement.

Twelve other militants were killed in fighting in Maiwand, a separate district also in Kandahar province.

The governor of Kandahar, Asadullah Khalid, said the Taliban had controlled 10 towns in the Arghandab district, but government and NATO forces took back four of them.

Khalid said that "a large number" of Afghans have been displaced by the fighting — other officials estimated thousands had fled. He said officials have requested help from the U.N.

Helicopters and jets patrolled the skies and smoke rose from fields after exchanges of fire, an Associated Press reporter in Arghandab said. A helicopter landed in a field near the fighting and appeared to evacuate a casualty, he said. Large Canadian military vehicles and Afghan police trucks moved through the region.

NATO and Afghan forces were moving carefully through Arghandab to minimize civilian casualties and to avoid any bombs planted by insurgents, said Maj. Gen. Carlos Branco, a spokesman for the NATO-led force.

"We are not in a hurry," he said. "The resistance that we face so far has not been significant."

Gen. John Craddock, NATO's Supreme Allied Commander of Europe, wrapping up a visit to Afghanistan, pointed to the Afghan army's response to Arghandab as "an excellent example of its increasing capability," a NATO statement said.

"The fact of the matter is that in less than 24 hours notice the Afghan National Army moved a battalion of soldiers to Kandahar, by using both their own airplanes and ISAF aircraft, from a cold start," Craddock said. "There are not too many nations in the world capable of such a response."

Ahmed Wali Karzai, the brother of Afghan President Hamid Karzai and the director of the Kandahar provincial council, said more than 1,500 families had sought refuge in Kandahar out of fear, many staying with relatives.

Meanwhile, the British Ministry of Defense said four British soldiers were killed when an explosive was detonated against their vehicle during a patrol in neighboring Helmand province on Tuesday. At least one soldier was wounded.

It was one of the deadliest attacks of the year on international troops in Afghanistan. Four U.S. Marines were killed in a roadside bomb in earlier this month, but prior to that, no more than three international troops had been killed in any one attack in the country this year.

Two NATO soldiers died and 10 were wounded Wednesday in Paktika province, NATO said. No other details were released, including the soldiers' nationalities. Most soldiers in Paktika are American.

The Taliban assault on the outskirts of Kandahar was the latest display of strength by the militants despite a record number of U.S. and NATO troops in the country. The push into Arghandab came three days after a Taliban attack on Kandahar's prison that freed 400 insurgent fighters.

The Taliban regime ousted from power in a 2001 U.S.-led invasion of Afghanistan regarded Kandahar as its main stronghold, and its insurgent supporters are most active in the volatile south of the country.