A classified document leaked by the Taliban detailing security arrangements for an upcoming meeting to discuss strategic relations with the United States has been confirmed as authentic by senior Afghan officials.

Senior police and intelligence officials told Al Jazeera on Monday that although the leaked plan was real, almost all of the arrangements had been changed since the security breach.

In an email sent to journalists from a verified Taliban account on Sunday, the group’s spokesman said that "with help of infiltrators, we have obtained the security plan, maps, and some other important documents for the so called Loya Jirga [assembly of elders]".

Al Jazeera’s Bernard Smith, reporting from Kabul, said: “We are being told that the plan that the Taliban sent to journalists was the security plan. And indeed we are being told that the security forces were forced into a hasty rewrite of some 80 per cent of the plan.”

The consultative meeting, known as the Loya Jirga, was scheduled to begin on November 16. The meeting brings together representatives from Afghan provinces, ethnic groups, and civil society to discuss stalled peace talks with the Taliban as well as crucial negotiations about the US.

Both the US and the government of Hamid Karzai, the Afghan president, are hoping this meeting might provide the legitimacy necessary to sign an agreement which would pave the way for relations beyond 2014, when US forces are scheduled to withdraw.

Propaganda war

The confirmation of the leaked document comes as Afghan security forces on Monday shot dead a would-be bomber outside the meeting's venue.

The man, who was caught carrying a bomb near the entrance to the site, was shot before he could detonate the explosive, Sediq Sediqqi, an Interior Ministry spokesman, said. Two accomplices were arrested, Afghan intelligence service said in a statement.

“We seem to have an intensifying propaganda war as well as an actual war. On the one side, the Taliban seem determined to stop this [meeting] and are trying to intimidate some 2,300 delegates that are expected to attend the start of the jirga on Wednesday," Smith said.

He continued: “On the other side, you have the Afghan government that is determined this convention goes ahead because it wants to prove that at least in Kabul they have got the security ability to allow such an even to pass off peacefully."

The Taliban targeted last summer’s Loya Jirga with suicide bombers and rockets as the president addressed the assembled crowd of nearly 1,600 leaders.

The minister of interior and the chief of intelligence were fired immediately after the convention for failing to protect it

This year, the government has deployed extra forces across the city, hoping to protect the event as proof of a growing ability to control security in the country.