Afghan poll crisis: Kerry in Kabul bid to ease tensions

US Secretary of State John Kerry has arrived in Afghanistan to try to help resolve tensions over the country's disputed presidential elections, the BBC reported.

He will meet both of the candidates claiming victory in June's run-off, Abdullah Abdullah and Ashraf Ghani.

Mr Kerry earlier warned against a power grab, amid reports that Mr Abdullah was planning a "parallel government."

President Hamid Karzai is stepping down after more than 10 years in power after the US-led overthrow of the Taliban.

The fact Mr Kerry made this trip at such short notice, is an indication of just how concerned the US is about the risk of Afghanistan descending into post-election turmoil, the BBC's Aleem Maqbool in Washington reports.

It has become clear that seeing the way Iraq has unravelled so dramatically after US troops' withdrawal has made the White House all the more desperate that Afghanistan should fare better, he says.

Mr Kerry is also due to hold talks with the current president in Kabul.

America's top diplomat earlier warned that Afghanistan risked losing security and aid support if anyone tried to "take power by extra-legal means."