A bomb blast targeted lawmakers touring a factory north of Kabul Tuesday, killing at least 28 people, including five parliamentarians, a lawmaker said.

The blast was one of Afghanistan's bloodiest attacks since the fall of the Taliban in 2001.

The bomb blast went off outside a sugar factory in the northern province of Baghlan as the lawmakers were about to go inside. The blast struck school children, Afghan elders and government officials who had gathered to greet the visiting delegation of 18 lawmakers from the lower house, officials said.

The Ministry of Interior said at least 28 people were killed in the blast, but a doctor at Baghlan's main hospital, Dr. Mohammad Yousuf Fayez, said dozens of dead bodies may also have been left at the blast site and collected by families, meaning they wouldn't have been counted officially. Earlier, a high-ranking government official said 64 people had died.

A provincial official told Reuters that at least 50 were killed in the bombing, but that number could not be confirmed.

The BBC, meanwhile, reported that at least 40 people were killed or wounded. That number could also not be confirmed.

At least 42 school children were among 81 people wounded, Fayez said.

"The children were standing on both sides of the street, and were shaking the hands of the officials, then suddenly the explosion happened," Fayez said.

Shukria Barakzai, a lawmaker, said 18 of the 249 lower house parliamentarians had traveled to Baghlan province, and that 13 were dead or "in danger."

Baghlan lies about 150 kilometers (95 miles) north of Kabul.

President Hamid Karzai's office confirmed the deaths of five parliamentarians.

"This heinous act of terrorism is against Islam and humanity and I condemn it in the strongest possible terms," Karzai said in a statement. "It is the work of the enemies of peace and security in Afghanistan."

Kamin Khan, a police official, said people "everywhere" were dead and wounded, including police, children, lawmakers and officials from the Department of Agriculture. Afghanistan's major television station, Tolo TV, reported more than 100 people killed and wounded.

Among the lawmakers killed was Sayed Mustafa Kazimi, a former Afghan commerce minister and a powerful member of the Northern Alliance, said the lawmaker's secretary, Ahmadi, who gave only one name. Kazimi also served as the spokesman of the largest opposition group in Afghanistan, the National Front.

The northern Afghan region where the blast happened is known for tensions between the mainly ethnic Tajik government leadership and remnants of the militant group Hezb-i-Islami, whose fugitive leader Gulbuddin Hekmatyar, an ethnic Pashtun, is allied to Usama bin Laden and Al Qaeda but has denied organizational links.

Interior Ministry spokesman Zemeri Bashary did not confirm the deaths of any parliamentarians, saying several had been taken to the hospital. He said the lawmakers were part of parliament's economic commission.

He said the government was trying to tally all the wounded and dead at the different hospitals.

He blamed the attack on the "enemy of Afghanistan, the enemy of the people of Afghanistan," a term commonly used here to refer to Taliban militants but that could also include other terrorist groups like Al Qaeda.

In central Afghanistan, 60 Taliban militants on motorbikes and pickup trucks overran a district center, firing on the town from a mountain outlook, pushing out the police and cutting off the town's main road, the provinvial governor said Tuesday.

The Kajran district, in Day Kundi province, is the third overrun by militants in the last week.

Day Kundi's governor, Sultan Ali Uruzgani, said police retreated late Monday when 60 Taliban on motorbikes and trucks stormed the town. One militant was killed and one policeman wounded in fighting, he said.

Fighting broke out around Kajran five days ago, he said. Since then, the Taliban have been firing artillery into the town from a mountain overlook and on Monday blocked the main road, Uruzgani said.

Uruzgani said he asked the Afghan government and NATO for reinforcements but that the area hasn't received any such support yet. The district borders Helmand and Uruzgan provinces, which have both seen heavy fighting this year.

Two other parliamentarians were killed in attacks in Kabul earlier this year. More than 5,700 people have been killed in insurgency-related violence, according to an Associated Press count based on figures from Western and Afghan officials.

In the central Afghan province of Day Kundi, 60 Taliban militants on motorbikes and pickup trucks overran a district center, firing on the town from a mountain outlook, pushing out the police and cutting off the town's main road, the provincial governor said Tuesday. The Kajran district, in Day Kundi province, is the third overrun by militants in the last week.

In the south, rockets hit a small Canadian military outpost in Kandahar province Tuesday while Canada's defense minister, Peter MacKay, was visiting. A rocket landed in a cloud of smoke and dust about 50 yards from soldiers and reporters, who dived to the ground for cover. MacKay was not hurt.

The Associated Press contributed to this report.