ISLAMABAD – American drone strikes inside Pakistan are killing far fewer civilians than many in the country are led to believe, according to a rare on-the-ground investigation by The Associated Press of 10 of the deadliest attacks in the past 18 months.

The widespread perception in Pakistan that civilians, not militants, are the principal victims — a view that is fostered by leading right-wing politicians, clerics and the fighters themselves — fuels pervasive anti-American sentiment and, some argue, has swelled the ranks of al-Qaida and the Taliban.

But an AP reporter who spoke to about 80 villagers at the sites of the 10 attacks in North Waziristan, the main sanctuary for militants in Pakistan’s northwest tribal region along the Afghan border, was told that a significant majority of the dead were combatants.

Indeed, the villagers told The Associated Press that of at least 194 people killed in the attacks, about 70 percent — at least 138 — were militants. The remaining 56 were either civilians or tribal police, and 38 of them were killed in a single attack on March 17, 2011.

Excluding that strike, which inflicted one of the worst civilian death tolls since the drone program started in Pakistan, nearly 90 percent of the people killed were militants, according to villagers.

However, the civilian deaths in the covert CIA-run program raise legal and ethical concerns, especially given Washington’s reluctance to speak openly about the drone strikes or compensate the families of innocent victims.

U.S. officials who were shown the AP’s findings rejected the accounts of any civilian casualties but declined to be quoted by name or make their own information public.

The United States has carried out at least 280 attacks since 2004 in Pakistan’s tribal region. The area is dangerous and off-limits to most journalists, and death tolls from the strikes usually rely on reports from Pakistani intelligence agents who speak on condition of anonymity.

The numbers gathered by the AP turned out to be very close to those given by Pakistani intelligence on the day of each strike, the main difference being that the officials often did not distinguish between militants and civilians.