The results from the past week showed that after tallying 17 percent of the votes, Karzai had 43 per cent while Abdullah Abdullah had 34 per cent.
However, election officials advised not to form conclusions from initial samples. The updates would be provided till Thursday, Sep 3.
The results also revealed that out of 30 million people only 5.5 million had cast their votes.
It suggested a disappointing turnout of only about 5.5 million voters in a country of some 30 million people. Approximately 15 million of the total population are eligible voters.
The election day in south Afghanistan witnessed Taliban attacks and faced threats, which scared many voters.
Obama in May 200 had ordered the installation of 30,000 extra US troops against the Taliban insurgency.
Of 100,000 Western troops around 63,000 are Americans.
Casualties.org, a website compiling official figures stated that in 2009, around 295 foreign troops were killed Afghanistan.