A suicide car bomb detonated outside the Indian Embassy in Afghanistan's capital Monday, ripping through the building and killing at least 41 people, including two senior diplomats.

About 140 people were injured, officials said.

The attack is the deadliest in Kabul since the fall of the Taliban in 2001, and the worst in Afghanistan since a suicide bomber killed more than 100 people at a dog-fighting competition in Kandahar province in February.

Officials say a Toyota Corolla packed with explosives tried to follow a convoy entering the embassy. A security guard stopped the car and the suicide bomber detonated the explosives, damaging two embassy vehicles and ripping through the building's front wall, where dozens of Afghans were standing in line to pick up Indian visas.

India's External Affairs Ministry said its defence attaché and the embassy's press councillor were killed, along with two other Indian nationals and an Afghan security guard.

Freelance journalist Tom Coghlan told CBC news from Kabul that most of the dead and injured in the attack were ordinary Afghans, including women and children.

Coghlan said there will be many questions asked about how suicide car bombers managed to strike in what was supposed to be a highly secure area, ringed by checkpoints and concrete blast barriers.

"Afghanistan's capital is surrounded by a ring of steel," he said, "with checkpoints manned by Afghan police and an outer ring of NATO troops, yet a suicide bomber has managed to slip through."

Security officials say insurgents were probably behind the attack, but the Taliban has denied any role in the carnage. The group often denies being associated with violence that takes civilian casualties.

Hospital runs out of space

Shortly after the attack, a woman ran out of a Kabul hospital screaming, crying and hitting her face with both of her hands. Her two children, a girl named Lima and a boy named Mirwais, had been killed.

"Oh my God!" the woman screamed. "They are both dead."

Kabul's largest public hospital ran out of space and officials resorted to storing some bodies in makeshift morgues, freelance journalist Kim Brunhuber reported from Kabul for CBC.

"One of the dead that I saw was a young student and his timetable was on him covered in blood," said Brunhuber.

Smouldering ruins covered the busy street in the city centre and the blast rattled much of the capital.

The Indian Embassy is near Afghanistan's Interior Ministry, as well as other embassies including Indonesia's and Canada's.

Five Afghan security guards were killed at the Indonesian Embassy, where windows were shattered and doors and gates broken. Two diplomats were slightly wounded, Indonesia's Foreign Ministry said.

Officials with the Canadian Embassy said no one there was injured.

Karzai condemns bombing

Afghan President Hamid Karzai condemned the bombing and said it was carried out by militants trying to rupture the friendship between Afghanistan and India.

The Interior Ministry, meanwhile, hinted that the attack was carried out with help from Pakistan's intelligence service, saying "terrorists have carried out this attack in co-ordination and consultation with some of the active intelligence circles in the region."

Pakistani Prime Minister Syed Yousuf Raza Gilani said his country's intelligence agency was not involved in the suicide bombing and his country has no interest in destabilizing Afghanistan.

In New Delhi, Indian officials said the attack would not deter their diplomatic mission from "fulfilling our commitments to the government and people of Afghanistan."

Afghanistan Foreign Minister Rangeen Dadfar Spanta visited the embassy shortly after the blast, ministry spokesman Sultan Ahmed Baheen said.

"India and Afghanistan have a deep relationship between each other. Such attacks of the enemy will not harm our relations," Spanta told the embassy staff, according to Baheen.

The Indian ambassador and his deputy were not inside the embassy at the time of the blast, Baheen said.

Frequent attacks on Indian offices, projects

Militants have frequently attacked Indian offices and projects around Afghanistan since launching an insurgency after the ouster of the Taliban at the end of the 2001. Many Taliban militants have roots in Pakistan, which has long had a troubled relationship with India.

When the Taliban ruled Afghanistan in the late 1990s, the Islamic militia was supported by Pakistan, India's archrival. Pakistan today remains wary of strengthening ties between Afghanistan and India.

The UN sent an e-mail to its staff advising them to stay off Kabul's roads because of reports that a second suicide car bomber was in the city.

Just last week, the Indian embassy had beefed up security by installing large, dirt-filled blast walls often used by military forces.

While Afghanistan has seen increasing violence in recent months, Kabul has been largely spared the random bomb attacks that Taliban militants use in their fight against Afghan and international troops.

In September 2006, a suicide bomber near the gates of the Interior Ministry killed 12 people and wounded 42 others. After that blast, additional guards and barriers were posted on the street.

Earlier this year, militants attacked Kabul's only five-star hotel, killing six people including an American and a Norweigan. Insurgent gunmen also stormed a military parade in the Afghan capital in April, forcing President Karzai to flee for his life.

In two separate bombings Monday against police convoys in the country's south, seven officers were killed and 10 others were wounded, officials said.

In Uruzgan province, a roadside bomb killed four police on patrol and wounded seven others, said provincial police Chief Juma Gul Himat.

In the Zhari district of Kandahar, another roadside blast killed three officers and wounded three others, said district Chief Niyaz Mohammad Sarhadi.

With files from the Associated Press