(IsraelNN.com) A Grad Katyusha rocket killed one person in the center of Ashkelon and wounded 16 others Monday morning as Hamas continues to attack Israel. The worker who died was identified as Hani Elmahadi, 27, from the Bedouin city of Aroer.

Three people were seriously wounded, and 13 others suffered light wounds and shock. All of the victims apparently were Bedouin and Galilee Arab construction workers.

Ashkelon Mayor Benny Vaknin, who reported the attack in the middle of an on-the-air interview with Voice of Israel government radio, said that the rocket hit a building under construction. Witnesses reported the explosion was extremely powerful and broke through a concrete floor eight-inches thick. 

He said it was "a miracle" that many more were not wounded in the explosion, which occurred several feet away from a heavily populated area. Vaknin declined to identify the area for security reasons.

As he spoke on the radio, Magen David Adom ambulances arrived at the scene within two minutes and evacuated the wounded to the port city's Barzilai Hospital.

Eight other rockets, most of them Kassams, followed in the next two hours but did not cause injuries or damage.  Ashkelon is home to oil and gas pipelines, security installations and large power generating plant.

Several Kassam rockets exploded in Sderot shortly before 11 a.m. (4 a.m. EST) and shortly after noon, causing extensive damage in the center of town and next to a nearby house. Several people were treated for shock. One other rocket hit a nearby kibbutz as people began going to work shortly before 8 a.m., and two others struck near Netivot. No one was injured, and no damage was reported.