KABUL, Afghanistan — On the deadliest day in Afghanistan this year, 22 civilians were killed and 50 were wounded Wednesday in two suicide bombings in the restive southern province of Kandahar, while 18 civilians were reported killed in a U.S.-led coalition airstrike in eastern Logar province.

Coalition officials disputed Afghan reports of civilian casualties in the predawn airstrike, which they said was ordered after a joint Afghan-coalition force came under fire from insurgents while trying to capture a Taliban leader in the district of Baraki Barak. An Afghan provincial official in Logar alleged that many of the victims were young children, but it was impossible to confirm the accounts immediately.

“At this point, our understanding is still that there were no civilians killed as a result of that operation,” said a spokesman for the International Security Assistance Force, Navy Lt. Cmdr. Brian Badura. Coalition officials said late Wednesday that a team would investigate the allegations.

The airstrike took place early Wednesday after the U.S.-Afghan operation raided a house where a supposed Taliban meeting was taking place at about 2:30 a.m., said Ghulam Sakhi, the Logar provincial police chief. Three U.S. soldiers and three Afghan soldiers were wounded in an exchange of fire with insurgents, who refused to surrender, prompting coalition forces to order the airstrike. Sakhi said 18 civilians were killed, in addition to 12 people whom he identified as Taliban.

Dr. Abdul Wali Wakil, the head of the Logar provincial council, told McClatchy that two men and two women were among the dead, as well as three teenagers whose ages he listed as 13 to 15. The rest he described as children – many of whom were 3 to 5 years old – who were members of the same family.

In an earlier statement, coalition forces said only that a team that had visited the site after the airstrike “discovered two women who had sustained non-life-threatening injuries” and that those women were transported to a coalition medical facility.

Even if the 18 civilian deaths at Logar aren’t confirmed, the attack at Kandahar made Wednesday the bloodiest day in Afghanistan since a suicide bomber struck a Shiite Muslim shrine at Kabul in December, killing 84 civilians and wounding as many as 200.

The Kandahar attack occurred in the late morning at a rest stop on the highway between the city of Kandahar and Spin Boldak, a town on the Pakistani border, said Javid Faisal, a spokesman for Kandahar’s governor. Faisal said the first attack was by a suicide bomber riding a motorcycle, and that after people had gathered at the site of the attack, a second suicide bomber, who was on foot, detonated his explosives.

The Taliban claimed responsibility for the attack in a statement on their website, saying they’d targeted a rest stop used by a private security firm that supplies foreign forces in Afghanistan. The group said that only one suicide bomber was involved and it claimed that the attack had killed and wounded coalition soldiers.

Faisal rejected the claim. “The suicide bombers targeted civilians,” he said. “There were no Afghan or ISAF soldiers or police present. There is no military base there.”

Shortly after the attack, bodies were being cleared from the scene and the wounded were being transported to hospitals. Faisal said the number of casualties could rise, although 30 of the 50 civilians who were wounded appeared to have minor injuries.

President Hamid Karzai, who was in China for a summit of regional leaders, condemned the attack, saying in a statement that the Taliban “will not achieve their goals by conducting such cowardly attacks.”

Also Wednesday, two coalition service members died after a helicopter crash in eastern Afghanistan. The coalition refused to release details about the cause of the crash or its precise location, but it said it was investigating the incident.

Taliban spokesman Zabihullah Mujahid said in a statement that Taliban insurgents had shot down a U.S. helicopter in the eastern province of Ghazni, but there was no independent confirmation of the claim.

Separately, one civilian was killed and 10 were wounded in a suicide attack late Wednesday in northwestern Faryab province, according to Faryab’s health director, Abdul Ali Haleem. Faryab’s police chief, Abdul Khaliq Aqsaee, said an Afghan soldier identified the bomber, who denoted his explosive vest while running away.

On Tuesday, three people were killed when an anti-vehicle mine exploded on the main road of Dowab village in Ghazni, Afghan officials said. Another was wounded in the blast. The Interior Ministry blamed the attack on “the enemies of peace and stability,” shorthand for the Taliban-led insurgents who are battling coalition forces and Karzai’s government.