By Mark Dummett and Bilal Sarwary
BBC News, Khost
It is only 200km (125 miles) from Kabul to Khost, but Afghanistan's capital has little control over this rugged border province.
The DVDs are available on both sides of the border
Government officials in Kabul say well-armed fighters cross regularly from next-door Pakistan, but admit they can do little to stop them.
In remote areas, more than $5,000 (£2,865) in bounty money has been offered to local men to kill senior government workers, one administrator said.
"It is big money. It is al-Qaeda money and it is from the Gulf," he said, referring to Arab supporters of al-Qaeda.
Khost's beleaguered local government blames Pakistan for this situation.
It says militants have been allowed to set up training camps near the town of Miranshah, in the tribal areas across the border.
Some of these camps have been filmed and the DVDs that are then distributed in both countries.
The films are used to terrorise opponents and recruit new fighters, or sent abroad to help raise money.
Their commentaries are often in Arabic, over a soundtrack of religious singing.
Their producers appear keen to make an explicit link between the wars in Afghanistan and Iraq.
A leading cleric who was killed by the Taleban in Khost
One recently distributed DVD shows an Afghan man confessing to being a spy for the US.
He is then beheaded in front of a photograph of the leader of al-Qaeda in Iraq, Abu Musab al-Zarqawi.
A second shows the Taleban-style public execution of a number of men accused of being criminals, then their headless bodies being dragged behind a car along the streets of Miranshah.
A third DVD follows a group of about 10 fighters, some of whom appear to be Arab or Uzbek, learning how to fight in a training camp. The DVD then shows scenes which it says shows the fighters attacking and over-running an ANA post in Khost province.
"The militants are well equipped with the latest weapons, ammunition and money, and they cross the border," the local administrator said.
Although the insurgents launch deadlier attacks in southern Afghanistan - where the UK is now leading the new deployment of Nato troops - a resident of Khost said there was a skirmish, a roadside explosion or a shooting roughly every other day.
Villages on the border with Pakistan are out of government control
That was enough, he said, to frighten away any investment in desperately needed schools, clinics or other infrastructure.
According to Colonel James Yonts, spokesman for the US-led coalition in Afghanistan, the militants have changed their tactics in the past year, and are launching more attacks, sometimes suicide attacks, against civilian targets.
This was an attempt to undermine the reconstruction of Afghanistan and "break the will of the people", he said.
"They are not winning, they are desperate," he added.
Last week, Afghan President Hamid Karzai was in Islamabad to urge Pakistan to step up pressure on the militants.
The same day a BBC reporter visited the frontier village of Makhay Kandaw.
In spite of the fact that Pakistan-based fighters are believed to have recently entered Afghan territory near here several times, there was no sign of any official security presence, and there were no roadblocks on the way.
Officials say suicide attacks are increasing in number
"It was like the doors to a hotel were wide open," the reporter remarked, "but there was no-one at the check-in desk."
While President Karzai stopped short of accusing Pakistan of supporting the attackers, the governor of Khost province, Mirajudin Pattan, did not.
"The Taleban and al-Qaeda militants have training camps inside Pakistan and the Pakistani government is helping them," he told the BBC.
"Several times they have sent suicide attackers to kill me, but they have failed," he said.
For its part, the Pakistani government defends its record.
It says it does all it can to stop the militants from operating on its soil.
It has arrested scores of suspected al-Qaeda agents and sent thousands of troops into the autonomous tribal regions which border Afghanistan.