By Jannat Jalil BBC correspondent in Kabul

Dostum's faction is fighting for control of the north

The fighting between the forces of Abdul Rashid Dostum and Atta Mohammed comes even as British troops are preparing to set up a reconstruction project in the main city in the north, Mazar-e-Sharif.

It is just the latest in a long line of battles between the two factions who have fought for control of the north since the Taleban was overthrown a year-and-a-half ago.

Dozens of people have been killed in clashes, yet the two warlords have been able to carry on fighting because an international peacekeeping force has only been established in Kabul.

Karzai's pleas 'unheard'

President Hamid Karzai has therefore been unable to assert his control beyond the capital, as provincial leaders - often with sizeable private armies - have fought each other or entrenched their positions in different parts of the country.

Central authority does not extend far beyond Kabul

This threatens to undermine reconstruction efforts in Afghanistan.

Mr Karzai's repeated requests for international peacekeepers to cover the whole of Afghanistan, not just Kabul, have been turned down.

Instead, joint military and civilian teams are being established in eight parts of the country.

About 50 British troops are preparing to set up one of the teams in Mazar-e-Sharif.

As well as taking part in reconstruction work, the team is supposed to help in the demobilisation of private militias.