Afghan intelligence agents said on Thursday they are investigating links between Pakistan and Taliban militants who killed 26 people in three simultaneous suicide bomb and gun raids on state offices in the capital Kabul.

The three coordinated raids on two ministries and a prisons department office on Wednesday show a new tactic by the Taliban, who have previously only attacked one target at a time.

The raids may have been inspired by last year's attacks in Mumbai, India, and were designed to cause maximum panic and publicity, but analysts said Afghan forces blunted the effect by acting quickly to kill the militants.

"As they were entering the Ministry of Justice before starting their indiscriminate killing of the civilians in there, they sent three messages to Pakistan calling for the blessing of their mastermind," Afghan intelligence chief Amrullah Saleh said.

The National Directorate of Security is investigating the possible link to Pakistan, a spokesman for the state intelligence agency said on Thursday.

Since the beginning of last year, the Taliban and their allies have launched fewer attacks inside the heavily guarded capital, but those they have carried out have tended to be against high-profile targets designed to grab media attention.

Wednesday's attacks also came on the eve of the first official visit to Afghanistan by President Barack Obama's new regional special representative, Richard Holbrooke.

"These suicide bombers were not the ordinary Taliban type of suicide bombers who come and blow themselves up somewhere. They had rifles as well and their aim was not to immediately explode themselves," said Haroun Mir, political analyst and co-founder of the Afghanistan Centre for Research and Policy Studies.

"It was in my opinion to take hostages and continue the way they did in Mumbai, to paralyse Kabul and hopefully inflict a big blow to Mr. Holbrooke's trip to Afghanistan. This trip is a very important trip to Afghanistan."

AFGHAN TROOP SUCCESS

India says the militant plan to attack Mumbai that killed 179 people last November was hatched in Pakistan, something the Pakistani Interior Ministry said on Thursday was partly true.

Afghan officials have repeatedly accused Pakistan of allowing Taliban militants to train and equip in the lawless tribal regions close to the rugged frontier with Afghanistan.

Elements within Pakistan's intelligence services secretly back the Afghan Taliban in order to keep Afghanistan weak and secure Pakistan's rear, allowing Islamabad's forces to concentrate on defending the border with India, analysts say.

Holbrooke, charged with unravelling the age-old regional rivalries, admitted ahead of his current visit to Pakistan, Afghanistan and India he faced a "tougher challenge than Iraq".

NATO troops in Afghanistan are locked in a stalemate, especially in the south, where mainly British, Canadian and Dutch forces have seen the Taliban come back time and again because they do not have enough troops to hold territory.

Obama is expected to decide in the next few days how many extra U.S. troops to send to Afghanistan to try to break the stalemate. But while almost doubling U.S. troop numbers to 60,000 is an option, the long-term solution and exit strategy for Washington is to train up Afghan forces to do the job themselves.

The United States is committed to increase the Afghan army from 80,000 troops at present to 134,000 in the next three years and has begun cleaning up the notoriously corrupt police.

While Wednesday's raids exposed gaps in Kabul's security, the action of Afghan forces in shooting dead three of the eight attackers before they were able to enter the government offices, then swiftly storming the buildings and killing the rest certainly limited what could have been a much deadlier incident.

"This highlighted the success of the Afghan security forces, because they didn't allow them to take control of these ministries," said Mir.

"Indian forces (in Mumbai) wasted a lot of time just deciding whether to enter or not," he said.

"This was not a sophisticated attack that had the huge amount of damage that it could have had. It was actually very poorly executed and interdicted very well by the Afghan security forces," said U.S. forces spokesman Colonel Greg Julian.