A prominent Afghan lawmaker escaped a suicide attack on Tuesday, aides said, on the day that the handover of security from NATO to Afghan forces was to be announced.
An AFP photographer reported there were casualties at the scene.
The handover of the last 95 districts from NATO to Afghan forces includes many of the most volatile areas of south and east Afghanistan where the Taliban have fought a bloody insurgency against the US-backed government since 2001.
After the handover, 100,000 NATO forces will play a supporting and training role as Afghan soldiers and police take the lead in the fight against the militants who were ousted from power after the 9/11 attacks.
Doubts remain, however, over the ability of the 350,000-strong Afghan forces to thwart the Taliban, and the NATO military coalition will retain an important role in logistics and air support as well as in combat when required.
Recent attacks have demonstrated the Taliban’s ability to strike at Kabul as the country prepares for next year’s presidential elections and the NATO withdrawal by the end of 2014.
A suicide car bomb last Tuesday killed 15 civilians outside the Supreme Court in Kabul. The previous day, gunmen fired grenades at the city airport and an international aid group’s compound was targeted in a seven-hour battle late last month.