The British jet called in by the U.S. Marines had the Taliban position in sight, but the pilot refused to fire, a decision that frustrated Marines on the ground but one in line with new orders by the top U.S. commander to protect civilians.

The Marines themselves didn't attack militants shooting at them Wednesday because women and children were in the compound, an approach meant to avoid civilian casualties at all costs.

"They did that on purpose," sniper platoon leader 1st Lt. Joseph Cull, 28, of Delafield, Wisconsin, said of the Taliban. "They are trying to bait us."

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Gen. Stanley McChrystal, the top U.S. and NATO commander in Afghanistan, has made protecting Afghan civilians his top priority. The approach is a shift away from a military mindset whose traditional first response has been to kill as many militants as possible. By holding fire McChrystal hopes to avoid the massive civilian casualty cases of past months and years and help win over Afghan villagers.

U.S. Marines have been locked in battle with insurgents in Dahaneh in Helmand province after they stormed into the Taliban-held town early Wednesday. Militants have been lobbing rocket-propelled grenades, mortars and heavy machine gun fire at the U.S. troops.

The troops hope to break the Taliban grip in Dahaneh, sever smuggling routes and protect civilians from Taliban reprisals so Afghans can vote here during the Aug. 20 presidential election, which the Taliban have vowed to disrupt.

The Marines locked in on a Taliban position Wednesday in a cave in a nearby mountain, from which militants were firing heavy weapons. The troops called for an airstrike against the position, but the British Harrier jet that responded refused to fire its missiles because British rules of engagement require the pilot himself to identify the target, not just troops on the ground.

Each country in the more than 40-nation NATO-led coalition in Afghanistan has its own rules of engagement that apply to specific battle situations, but McChrystal's order to protect civilians applies to all forces in the country.

"Sure, that's frustrating, but we've got to deal with it," said Capt. Zachary Martin, commander of Golf Company, 2nd Battalion, 3rd Marines.

Some 400 Marines and 100 Afghan troops moved into Dahaneh early Wednesday by helicopter and ground convoy. The troops took heavy fire from insurgents for most of the day, killing up to 10 militants after calling in an airstrike on an insurgent position.

But even that airstrike was carried out with great care.

Militants first started firing from the position about 5 a.m. Ground commanders wanted an airstrike called in on the position to help protect Marines receiving fire. But superior officers wanted to be certain there were no civilians there. Once Martin had established with near certainty that there were not, an airstrike hit the compound — hours after the Marines first received fire.

The Marines say they can avoid civilian casualties with the help of the sophisticated surveillance technology they have. Strict orders have also been issued for the Marines to use proportional response when attacked.

But many of the riflemen voiced frustration at the limited options they were left with when trying to expand control of the town on Wednesday. The orders to hold fire appeared to have slowed their advance in Dahaneh, where after a full day they held only a small foothold outpost.

On Thursday the Marines expected another day of intense combat as they pushed deeper into the town. Insurgents seemed unwilling to fight overnight, when they can't match the Marines' night vision capabilities. But after the sun came up early Thursday, the first rounds of fire erupted.

"Right on cue!" shouted Sgt. Ryan Kelsey, of Pittsburgh, Pennsylvania, as the first shots rang out.

Elsewhere in Afghanistan, two separate roadside blasts in southern Afghanistan killed 14 civilians, including three children, underscoring the high price paid by ordinary people in the conflict with the Taliban, officials said Thursday.

Officials blamed the blasts on Taliban militants, who have made roadside bombings their primary weapons.

A blast on a road in the Gereshk district of Helmand province ripped through a vehicle carrying a family on Wednesday, killing 11 people, including two women and nine men, said Daud Ahmadi, the spokesman for the provincial governor.

In neighboring Kandahar province, three children were killed after they started playing with another bomb which they had found on the side of the road west of the provincial capital, police official Mohammad Shah Khan said. The victims were between 8 and 12 years old.

Southern Afghanistan is the center of the Taliban-led insurgency, where thousands of additional U.S. troops were deployed this year to try to reverse the militants' gains and create conditions for next week's presidential election.

According to figures from the U.S.-based Joint Improvised Explosive Device Defeat Organization, the number of incidents from IEDs soared to 828 last month, the highest level of the war and more than twice as many as in July 2008. The majority of the victims in such attacks have been civilians.