KABUL, Afghanistan (AP) -- Bomb attacks in Kabul and northern Afghanistan on Wednesday killed at least four people and wounded 13, officials said.
Two sticky bombs targeted government employees in the Afghan capital, killing two people, including a police officer, and wounding two others, police said.
Meanwhile in Puli Khumri, the capital of northern Baghlan province, a bomb targeted a vehicle belonging to the provincial intelligence department, killing two service members and wounding 11 people, including both military and civilians, said Nazir Najem, the provincial governor's spokesman.
No one immediately claimed responsibility for the attacks. Kabul police spokesman Ferdaws Faramarz said one of the sticky bombs was attached to a police vehicle, while the other was attached to a car belonging to the education ministry. The police were investigating, he said.
Taliban spokesman Zabiullah Mujahid said he was not aware of the explosions in Kabul.
Meanwhile, the Islamic State group claimed responsibility for a mortar attack the previous day in Kabul that killed three people, including two government employees, and wounded at least 16, including including four children and woman.
Tariq Arian, the Interior Ministry's spokesman, said militants fired a barrage of rockets from two vehicles toward different areas of the city. Earlier, reports said only that there were 10 wounded. The attacks came as Afghans on Tuesday marked their country's Independence Day.
The Islamic State group said it fired 16 mortar shells, targeting the presidential palace, embassies and Afghan government offices in Kabul. Authorities said most of the shells hit residential homes.
The violence comes amid new uncertainties over the start of talks between the Taliban and the Kabul political leadership. The government said it would not release the last 320 Taliban prisoners it holds until the insurgents free more captured Afghan soldiers.
The decision went against that of a traditional Afghan council held earlier this month — the Loya Jirga — and is likely to further delay intra-Afghan peace talks sought by the United States.