BBC:

The Taliban have infiltrated the Afghan army and police, a recently-retired United Nations official has warned.

Taliban flag

Dr Antonio Maria Costa, former head of the UN Office on Drugs and Crime, said Taliban sleeper cells had been set up inside the security forces.

They had already carried out a number of attacks and were planning further attacks on Nato-led troops, he said.

A spokesman for the coalition forces said infiltration was a rare problem and most Afghan troops were loyal.

Dr Costa's comments come as the coalition is preparing to hand over control of the country's security to Afghan forces by 2014, the BBC's Gerry Northam reports.

Meeting the handover target in four years requires 141,000 new recruits to be found within a year - more than the current size of the Afghan army.

There are fears that the Taliban are taking the opportunity to enlist insurgents into the ranks.

"We have plenty of evidence we had a number of suicide attacks carried out by people who had been in the army, trusted because they were affiliated," Dr Costa told the BBC.

Background:
Spanish TV publishes video of Spanish base (Qala-i-Naw)'s terrorist attack. The attack was carried out by an Afghan police member, linked with the Taliban.
Spanish TV publishes video of Spanish base attacked after Taliban terrorist attack.

A few days ago, a new video emerged showing the fighters taking part in target practice at a training camp in Afghanistan. In the 31-minute-long video, the five German-speaking jihadists claimed responsibility for two attacks on American military installations in Afghanistan.

They call themselves the German Taliban Mujahideen and are a relatively new group, according to Yassin Musharbash, an editor at German news portal Spiegel Online and an expert on Islamic terrorism.

“There seems to be between six and 10 German-speaking fighters who are in Afghanistan, apparently acting under the command of the Afghan Taliban,” he said. They appear to have made their first online appearance in the fall.

According to Musharbash's assessment, the German Taliban Mujahideen (DTM) formed from the scattered remnants of the Islamic Jihad Union (IJU), a relatively small group that had been active in Afghanistan for years. The four young men of the so-called "Sauerland" group in Germany also belonged to the IJU. They were sentenced to long prison terms in March for preparing planned terrorist attacks in Germany.

“It's my impression that the IJU has been mostly destroyed,” said Musharbash. Only a few sporadic traces remain of the group on the Internet. The marauding foreign fighters of the IJU apparently slipped under the wing of the Afghan Taliban. There, the German jihadists were able to form their own brigade, the DTM.

Musharbash speculated that their involvement in the attacks on the American and Afghan bases, referenced in the video, could have been a sort of internship for the men.

“The Afghan Taliban seem to have taken them along on two attacks - that's what it looks like to me,” he said. “And for their part, the German jihadists made a big propaganda video for the German-speaking public, to show that they're not just sitting around but actually taking part."

Germany has warned in the past about Jihadi families.

Background on the Sauerland cell: 1, 2, 3, 4, 5, 6. Other terrorist linked with them is German Taliban convert to Islam, Eric Breininger.

Related: The Third Generation.