The Islamic State has been reluctant to use humans to carry bombs because of the group’s reduced numbers, so it has tried out a new tactic: Bovine suicide bombers.

Residents of Al Islah, Iraq, on Saturday said they had witnessed “a strange” sight: two cows harnessed to explosive vests roving the northern side of the village, according to Col. Ghalib Al-Atyia, the spokesman for the police commander in Diyala Province.

The animals wandered into the outskirts of the community, and when they seemed close to houses, the bombs were detonated remotely, killing the cows, and damaging nearby houses, but not harming any people, Colonel Al-Atyia said.

In the colonel’s assessment, the attack signaled that the Islamic State, whose ranks were sharply reduced by the group’s four-year fight against Iraqi security forces backed by American special forces, was resorting to unconventional methods since they lacked manpower.