By Ian Pannell
BBC News, Kabul
**Preliminary results in Afghanistan’s presidential elections are due to be announced on Tuesday, election authorities have said. **Representatives for the two leading candidates, Hamid Karzai and Abdullah Abdullah, have already claimed to be ahead in the polls.
The announcement comes as the electoral watchdog investigates more than 700 complaints of fraud and irregularities.
A final result is not expected for several weeks.
The Independent Election Commission is expected to announce less than 20% of the total vote as counting and verification continues.
But it is also being urged to wait until the official election adjudicators complete their investigations.
There have been 790 complaints of which 54 are considered to be very serious.
The incumbent, Hamid Karzai, is considered to be ahead with the former Foreign Minister Abdullah Abdullah his nearest challenger.
The final results will not be known for more than three weeks.
But controversy continues to dog this election with allegations of fraud, corruption and ballot stuffing and concerns about low voter turnout, especially in the south.