Kabul, Afghanistan (CNN) -- In the fifth killing of a senior official in less than a week, the police chief of Afghanistan's Registan district was killed Monday morning by a roadside bomb.
Meanwhile, four International Security Assistance Force service members were killed by an improvised explosive device in separate attacks in eastern and southern Afghanistan.
One other ISAF soldier died of a non-battle related injury.
Monday's roadside bombing left Saleh Mohammad and three other police officers dead in the country's restive Kandahar province, according to provincial spokesman Zelmay Ayoubi.
Their deaths add to a growing casualty list, stemming from sporadic roadside attacks and high-level assassinations.
On Sunday, a key political adviser to Afghan President Hamid Karzai and a Parliament member were gunned down in a home west of Kabul.
The Taliban quickly claimed responsibility for the attack, and a gunbattle ensued between Afghan police and the remaining militants.
Last week, Kandahar's provincial council chief Ahmed Wali Karzai, the president's half-brother, was gunned down by a longtime bodyguard inside his home.
His assassination -- for which the Taliban also claimed responsibility -- highlighted security questions for many Afghan officials about who can be trusted.
During a remembrance ceremony for Wali Karzai at a Kandahar mosque two days later, a suicide bomber slipped into the building and killed six people and wounded 15 others.
A senior religious leader was among the dead in that attack.
The incidents have come about just as NATO forces are beginning the first stage of a troop drawdown, which is expected to remove 10,000 soldiers from Afghanistan by the end of of this year.
The full drawdown is scheduled for the end of 2014.
The attacks coincided with a separate Afghan-led security operation in the border province of Khost, which resulted in the detention of "numerous suspected insurgents" and the confiscation of "several weapons while searching for a Haqqani leader," ISAF reported.
The Haqqani network is an insurgent group -- believed to be based in Pakistan's lawless frontier territories -- that operates along the porous Afghan-Pakistan border regions.
Further to the north, security forces also detained a suspected insurgent while hunting a leader of the Islamic Movement of Uzbekistan, a militant group that operates out of neighboring Tajikistan and parts of Afghanistan.
CNN's Reshad Fazel and Matiullah Mati contributed to this report