KABUL (AFP/Reuters) - Afghan President Hamid Karzai Monday blamed intelligence failures, particularly on the part of NATO forces supporting his government, for the worst coordinated insurgent attacks in 10 years of war.

Karzai’s accusation came after an unprecedented 18-hour assault by squads of Taliban militants, some disguised as women in burqas, on government offices, embassies and foreign bases in Kabul and neighbouring provinces.

“The terrorists’ infiltration in Kabul and other provinces is an intelligence failure for us and especially for NATO and should be seriously investigated,” Karzai said in a statement.

Explosions and gunfire rocked the Afghan capital Sunday and overnight before Afghan forces regained control, heightening fears for the future of the vulnerable nation as NATO prepares to withdraw its 130,000 troops. The Western alliance, which is committed to pulling out by the end of 2014 whatever happens militarily, put a positive spin on the attacks, hailing the performance of Afghan security forces.

Karzai also praised the rapid response by Afghan security forces, saying it “proved to the people that they can defend their country successfully”. But his laying of the major share of the blame on troops whose home countries are already tired of the long war and its enormous cost, is unlikely to go down well with his allies.

Karzai’s office said 36 insurgents were killed in the attacks which paralysed Kabul’s government district, and which targeted three other provinces in what the Taliban called the start of a spring offensive. One fighter was captured. Eleven members of the Afghan security forces and four civilians were killed in the well-planned attacks in Kabul and the eastern Nangarhar, Logar and Paktia provinces, it said.

“In only a short time we managed to cut short their devilish plans,” said Defence Ministry Chief of Operations Afzal Aman. “They carried suicide vests, but managed to do nothing except be killed.” Insurgents were killed attacking the Afghan parliament, and in a multi-storey building under construction that they had occupied to fire rocket-propelled grenades and rifles down on the heavily fortified diplomatic enclave. More were killed in Kabul’s east, and while attacking a NATO base in the eastern city of Jalalabad. Fighting in the capital only ended with special forces assaults which were mounted as dawn broke.

Assisting physically for the first time in the attack, NATO helicopters launched strafing attacks on gunmen in the building site, which overlooked the NATO headquarters and several embassies, including the British and German missions.

Elite Afghan soldiers scaled scaffolding to outflank the insurgents, who took up defensive positions on the upper floor of the half-built structure. Bullets ricocheted off walls, sending up puffs of brick dust.

“I could not sleep because of all this gunfire. It’s been the whole night,” said resident Hamdullah. “I am enormously proud of how quickly Afghan security forces responded to (the) attacks in Kabul,” said General John Allen, commander of NATO’s ISAF. US Ambassador Ryan Crocker said the ability of Afghan forces to respond to the attacks was a “clear sign of progress”, while ISAF labelled the attacks “largely ineffective”.

However, the fact that so many militants managed to make it through Kabul’s so-called “Ring of Steel” checkpoints and attack high-value targets was a propaganda coup for the Taliban.

A Western diplomat with security expertise told AFP: “I don’t share at all the optimism of NATO or the Americans.

“It’s true that they did it better than in the past - there is progress but still, to build up so many attacks and being able to launch them simultaneously demonstrates clearly (the Taliban’s) ability to strike where and when they want,” he said on condition of anonymity.

NATO insisted that the attacks would not influence its plans to withdraw.

“Clearly we still face security challenges,” NATO spokeswoman Oana Lungescu told a news briefing in Brussels.

“But such attacks don’t change the transition strategy, they don’t change the goal and they don’t change the timeline that we all agreed to at the Lisbon summit in November 2010,” she said.

The US, British, German and Japanese embassy compounds came under fire as militants attacked the city’s diplomatic enclave and tried to storm parliament, sparking a gun battle as lawmakers and bodyguards fired back from the rooftop.

Outside the capital, militants attacked government buildings in Logar province, the airport in Jalalabad, and a police facility in the town of Gardez in Paktia province.

The attacks marked the biggest assault on the capital in 10 years of war in terms of their spread and coordination, observers say.