Police officers around the city are being warned about possible attacks using explosives made from household chemicals. The Daily News reports an alert went out to officers on Tuesday about so-called “Drano bombs” or “bottle bombs” made by mixing everyday chemicals in plastic containers.

The paper says officers were warned citywide but there’s particular concern about attacks in the Rockaways.

Police officials fear gang members are planning to target officers by tossing bottle bombs at them or placing them near patrol cars.

The News says none of the devices have been found yet.

(Source: NY1)