ISLAMABAD — Pakistani counterterrorism police in multiple raids arrested at least 12 suspects in connection with last week’s suicide bombing that killed five Chinese workers and their Pakistani driver in the volatile northwest, officials said Monday.

The detainees were not directly involved in the attack but they helped those who orchestrated Tuesday’s bombing targeting the Chinese, three police and security officials said. They said some of the detainees had links with Pakistani militants, adding that the suspects were still being questioned and other raids were ongoing.

The officials spoke on condition of anonymity because they were not authorized to speak to media on the record. The officials said some of the detained suspects transported an explosive-laden car to Shangla, a district in Khyber Pakhtunkhwa province, where a suicide bomber rammed it into another vehicle, killing the Chinese workers.

The latest development came hours after the bodies of the five Chinese nationals were flown overnight from a military air base in the garrison city of Rawalpindi to Beijing, Pakistani officials and state media said.