A land mine planted by Taliban insurgents in a police post in the Afghan capital killed three policemen on Wednesday, a police official said.
The blast occurred as a group of officers were investigating the killing of three other policemen at the post in an overnight Taliban attack, he told Reuters on condition of anonymity.
Several other police along with a senior city officer, Ali Shah Paktiawal, were wounded in the blast, which occurred in the western outskirts of the city, he added.
Focus on Kabul
The Taliban in a statement said the militant group was behind both incidents, adding they were part of the Islamists' focus on launching attacks in Kabul.
Taliban militants have closed in on the Afghan capital in the past year, making travel to the west, south and east of the city hazardous for aid workers and government officials.
Earlier, a police officer said the target of the blast was Paktiawal, who heads the criminal investigation department of Kabul police and has survived several attempts on his life.
U.S.-led and Afghan forces overthrew the Taliban's radical Islamist rule in 2001 for refusing to hand over al-Qaida leaders behind the September 11 attacks on the United States.
But the militants regrouped and have extended the size and scope of their attacks despite the rising number of foreign and Afghan forces, currently around 220,000.
They are mostly active in southern and eastern areas where frustration is high among many over civilian casualties caused by Afghan and foreign troops, the slow pace of economic change and the perception of lack of representation in the central government.