Militants launched a gun and suicide attack on an Afghan election commission office in Kabul, less than two weeks before the presidential poll.
The Taliban have vowed a campaign of violence to disrupt the ballot on 5 April, urging their fighters to attack polling staff, voters and security forces in the run-up to election day.
Blasts were heard at an Independent Election Commission office in the western Darulaman area of the Afghan capital.
The office is close to the home of Ashraf Ghani, who is seen as a frontrunner in the race to succeed President Hamid Karzai.
Interior Ministry spokesman Sediq Sediqqi said on Twitter that two civilians wounded in the attack had been taken to hospital.
A member of Mr Ghani's campaign team said the former World Bank economist was out of Kabul at the time, campaigning in the eastern province of Paktia.
IEC spokesman Noor Mohammad Noor said security forces had told them their office may be the target of the attack.
There was no immediate claim of responsibility but suicide bombings have been a key weapon for Taliban militants in their fight against Mr Karzai's government and its foreign backers since 2001.
Last Thursday, four gunmen stormed Kabul's Serena hotel and shot dead nine civilians including an Agence France-Presse journalist, an attack claimed by the Taliban.
The Serena attack came on the same day that seven Taliban suicide attackers invaded a police station in the eastern city of Jalalabad, killing ten policemen.
A week ago, a suicide bomber killed 16 people at a crowded market in the northern province of Faryab. There was no claim of responsibility for that attack.