Police officials say the bomb targeted a police patrol in the city of Dera Ismail Khan.
A bomb blast targeting police forces in northwest Pakistan has killed five people and injured 21, according to rescue and police officials.
The blast occurred in the city of Dera Ismail Khan, which has long been home to foreign and domestic armed groups.
The bomb exploded close to the route of a police patrol, police official Mohammad Adnan said. It was not immediately clear if the incident was the result of a suicide attack or a bomb planted nearby, he added.
Pakistan daily Dawn reported that the latest blast comes days after a policeman was killed when unknown gunmen opened fire on a police camp in Dera Ismail Khan.
Violence has risen in Pakistan this year, and it is primarily linked to the increased activity of Tehreek-e-Taliban Pakistan (TTP), a banned group ideologically aligned with the Afghan Taliban.
The country is also grappling with political and economic crises, which have led to a general decline in law and order.
August saw a sharp rise in militant attacks with 99 incidents reported across the country, the highest number in any single month since November 2014, according to the Pakistan Institute for Conflict and Security Studies.
Most of the attacks have occurred in the northwestern province of Khyber Pakhtunkhwa and its tribal districts. Incidents in the southwestern province of Balochistan, where a nationalist armed campaign has been going on for years, have also been common.
A caretaker government led by Prime Minister Anwaar-ul-Haq Kakar has been running the South Asian country since parliament was dissolved on August 9.
The country is set to hold delayed national elections on February 8 as security crises mount.
This story originally Appeared on Aljazeera