A suicide bomber has rammed a car full of explosives into the gates of the Indian embassy in the Afghan capital, killing 41 people, officials say.
More than 140 were injured, including civilians and security forces, BBC reports.
Defence attache Brig R Mehta, a senior Indian diplomat and two Indian security guards were among those killed.
No-one has admitted being behind the attack, one of the deadliest in Kabul for some time. The Taleban have vowed to step up their attacks in Kabul.
President Hamid Karzai said the attackers wanted to undermine good relations between Afghanistan and India.
India also condemned the "cowardly terrorists' attack". The US condemned the "needless act of violence", as did the European Union, which described it as a "terrorist attack targeting innocent civilians".
Afghanistan has seen a sharp increase in violence in the south and east.
The bomb exploded as people were queuing for visas at the embassy.
"I saw glass falling down from buildings, before the area was crowded with ambulances, police and forces of the International Security Assistance Force (Isaf)", Abdul Raziq, who was distributing newspapers at the time, told the BBC.
Ali Hassan Fahimi said shrapnel had landed into his office, which is close to the site of the blast.
"It was so strong... and our staff were shocked," he said.
Among those killed in the attack were five Afghan security guards at Indonesia's Kabul embassy.
Officials in Jakarta said they did not believe they were targeted, but it was simply because the two embassies were close to each other. India has close relations with Afghanistan. It has been funding a number of large infrastructure projects, correspondents say.
Afghan Foreign Minister Rangeen Dadfar Spanta visited the Indian embassy shortly after the attack, his 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," Mr Spanta told the personnel at the embassy, the spokesman said.
And the Indian government spokesman said: "Such acts of terror will not deter us from fulfilling our commitments to the government and people of Afghanistan."
Afghanistan's interior ministry said it believed the attack was carried out "in coordination and consultation with an active intelligence service in the region".
It did not specify. But in the past, Afghanistan has accused Pakistani agents of being behind a number of attacks on its soil.
In April, there was an assassination attempt against the Afghan President Hamid Karzai in the city.
And earlier in the year, Taleban militants launched an attack on the Serena hotel killing several people.
Kashmir leader offers resignation The chief minister of Indian-administered Kashmir, Ghulam Nabi Azad, has offered to resign ahead of a vote of confidence in his government.
His administration was reduced to a minority 10 days ago after a coalition partner, the People's Democratic Party (PDP), withdrew its support, reports BBC.
The PDP pulled out after angry protests by Kashmiri Muslims against a decision to transfer land to a Hindu shrine.
At least five people died and hundreds were wounded in the unrest.
Mr Azad announced his decision to quit in the state's summer capital, Srinagar.
Addressing the state assembly, the chief minister said he was going to the Raj Bhavan [state governor's house] to hand in his resignation.
Elections are due in Indian-administered Kashmir, the country's only Muslim majority state, in October.
The BBC's Altaf Hussain in Srinagar says the governor has the option of imposing federal rule in the state or asking Mr Azad to continue as the caretaker chief minister until fresh elections are held and a new government is elected.
The governor had asked Mr Azad to prove his majority in the house after the PDP pulled out of the government.
The Kashmir valley witnessed days of violent protests in recent weeks following the government's decision to grant 40 hectares of forest land to the Amarnath Shrine Board.
Muslims argued the move was aimed at altering the demographic balance in the valley.
The state government later rescinded its decision - which led to protests by Hindus in the state's Hindu-majority region of Jammu.
Demonstrations later spread to other parts of India, with hard-line Hindu groups accusing the Kashmir government of giving in to the demands of separatists.
Last Thursday four people died in Indore, in the central Indian state of Madhya Pradesh, when police opened fire during clashes between Hindus and Muslims over the issue, officials say.
