Residents in the Ramat Hasharon and Herzliya areas detected a strong smell in the air Monday morning for the second time in four days, Ynet reported.

As Environment Minister officials continue to search for the cause of a strong smell in the Sharon and Gush Dan areas last week, residents again reported  a stench from an unknown source. It is not clear if there is a connection between the two odors.

According to Ynet, officials are investigating whether work on a large gas tank at a restaurant in Ramat Hasharon last Thursday caused the odor in that area.

While various theories were suggested for last week’s strong smell, including offshore gas drilling or a ground disinfection procedure, the source of the odors has not yet been discovered.