Several key aides to the leader of Afghanistan's Taleban rebels, Mullah Omar, are reported to have been arrested in Pakistan.
By Charles Haviland
BBC News, Afghanistan
An Afghan intelligence source told the BBC four senior associates of Mullah Omar were being held after operations by Pakistani security forces.
The arrests took place in two areas of the city of Quetta in western Pakistan.
The source said those arrested included two men responsible for Mullah Omar's letters and communications.
They have been named as Mullah Jahangir and Mullah Mohid.
Others now in detention are said to be Mullah Nazir, who was Taleban commander in the southern Afghan province of Uruzgan, and Mullah Tahir, the former Taleban commander for the capital, Kabul.
Afghanistan observers say these four men were all close to the reclusive Mullah Omar, whose whereabouts remain unknown.
In the past year or more, there have been rising tensions between Afghanistan and Pakistan.
Some senior Afghan leaders accused their neighbour of letting the Taleban use its soil, including Quetta, as a sanctuary.
Pakistan denies such accusations and four months ago it arrested another key Taleban leader, Mullah Obaidullah, on its own soil.