A mix of explosions filled Gaza City's air late Thursday, but not all were blasts of war.
A celebration erupted as a mosque loudspeaker chant proclaimed: "God is great. We have hit Tel Aviv."
Rockets fired straight upward were not targeted at an enemy, but were aimed at raising spirits with claims that militant missiles launched from Gaza reached Israel's government center 45 miles (71 kilometers) away.
One Gaza-launched rocket landed just south of Tel Aviv Thursday, in an open area near Rishon LeZion, the Israel Defense Forces said.
Knowing that air sirens had sounded inside and outside the Israeli Defense Ministry in Tel Aviv apparently gave comfort to some of the Gaza residents who are facing the possibility of another full-scale war with Israel -- four years after the last one.
At least three Israelis were killed and four were wounded when a rocket struck an apartment building in the town of Kiryat Malakhi Thursday, an Israeli police spokesman said.
Under siege inside Israel
The sounds of Gaza also included frequent explosions signaling another Israeli airstrike hitting what the IDF called terror sites, including Hamas weapons, storage bunkers, weapons labs and workshops. The IDF reported it attacked 300 sites by late Thursday.
Eighteen people, including two children, were killed in airstrikes in Gaza Thursday, the health ministry in Gaza said. Of the casualties, nine were Hamas militants, a Hamas source told CNN.
Gaza City is filled with people, 1.6 million Palestinians packed into 139 square miles (360 square kilometers) surrounded and isolated through decades of distrust, anger and occasional war.
Q&A: Gaza strikes could be beginning of ground attack
The main commercial area of the city is usually filled with cars and people, but on this Thursday evening many of the shops were shuttered and the streets were nearly empty. With electrical service still working, the Gaza City skyline was lighted at dusk.
A massive explosion hours after sunset was immediately followed by a power outage and a darkened skyline, illuminated only by other blasts.
Tiny plumes of smoke rose on that skyline, pinpointing where Israel's Iron Dome missile defense system intercepted rockets from Gaza before the missiles reached the ground. The IDF estimated it stopped about 130 of the 300 fired by Thursday afternoon.
There was a huge gathering of people in Gaza on Thursday. Thousands crammed narrow streets for the funeral of Ahmed al-Jaabari, the popular head of the Hamas military wing killed in an airstrike Wednesday.