At least 2.2 million people voted in Afghanistan's presidential election with more votes to come, the election commission head Maulana Abdullah said on Sunday, indicating a very low turnout that could mar the result.

Tight security ensured the election took place on Saturday in relative calm, but low turnout and complaints about the voting system heightened concerns that an unclear result could drive the war-torn country of around 34 million into further chaos.

There were 9.67 million voters registered ahead of the election. Abdullah said turnout numbers had been received so far from 3,736 of 4,756 polling centers nationwide. Almost 800 centers had still to report their figures and the status of more than 200 other centers was also unclear.