Islamabad, Pakistan - A suicide attacker on a motorcycle has struck the vehicle of a senior police official in the northwestern Pakistani city of Peshawar, killing him and his guard, according to police.

Ashraf Noor, an additional inspector general of police in Khyber Pakhtunkhwa province, was on his way to work when the attack occurred on Friday morning.

Local police official Zaman Khan said three others were wounded in the explosion, which sent a plume of dark smoke rising above Peshawar's Hayatabad area.

There was no immediate claim of responsibility.

The attack was a latest in a series of attacks against the country's police services.

Earlier in November, senior official Hamid Shakil was killed in a roadside bombing that targeted his vehicle in the southwestern city of Quetta.

Last month, another roadside blast killed at least seven police officers and wounded 22 more when it targeted a truck carrying elite anti-terrorism police, also in Quetta.

Pakistan has been battling the Pakistan Taliban (TTP), an umbrella organisation of armed right-wing groups mainly based in the country's tribal areas, and its allies since 2007.

Violence has fallen sharply over the past few years, as the country's military has taken on the TTP and others in operations first in the tribal districts and later elsewhere.

The Pakistani military says it has killed more than 3,500 members of armed groups over that period and suffered more than 600 casualties among its ranks.

Al Jazeera is unable to independently verify those figures, as access to the conflict zones is strictly controlled.

While attacks have now become more infrequent, major bombings have continued to occur in urban centres in 2017, particularly in Quetta, where the military is also battling an armed ethnic Baloch separatist movement.

Follow Asad Hashim on Twitter: @AsadHashim