KABUL, Afghanistan — A roadside bomb in Afghanistan killed at least two children and wounded five other civilians in the southern Kandahar province, said Nasrat Rahimi, spokesman for the Interior Ministry, on Saturday.

No one immediately claimed responsibility for Friday's blast in Spin Boldak district. However, the Taliban are active in the province and have claimed earlier attacks.

Elsewhere, a blast caused by children playing with unexploded ordinance has killed a pregnant woman, said officials in the northern Parwan province.

Seven children and two other women were also wounded, said Qasim Sangin, the head of a local hospital. One child remained in critical condition.

An investigation found the unexploded ordinance was quite old, according to an official in the Parwan police chief's office. He spoke on condition of anonymity because he was not authorized to talk to reporters.

Afghanistan is littered with thousands of unexploded land mines, artillery shells, bombs and other ordinance, the grim legacy of four decades of war.

Two explosions shook the capital, Kabul, on Friday night but caused no casualties, said Firdaus Faramarz, spokesman for the city's police chief. The capital sees near-daily attacks from insurgents.

Taliban spokesman Zabihullah Mujahid claimed the attacks in Kabul.

Across Afghanistan, militant attacks have continued as the country prepares for next week's presidential elections.

U.S.-Taliban talks over a peace deal have collapsed.