On Tuesday evening, Israeli Prime Minister Benjamin Netanyahu addressed the nation from Tel Aviv, saying, "We are in the midst of a significant operation" as fighters from Gaza fired a barrage of rockets toward Israel

Rockets were fired toward Tel Aviv in the early hours of Wednesday morning. Sirens could be heard warning of an impending attack around 3 a.m. local time. It was not immediately clear if there were any casualties.

In the town of Ashkelon, two people were killed by rocket fire on Tuesday, according to an Israeli military spokesman. A third person died in the town of Rishon Lezion, south of Tel Aviv on Tuesday evening after a rocket attack, Israeli media reported citing the ZAKA emergency service.

A CNN team heard at least 50 explosions in the coastal town near Gaza, and rocket fire was also reported in the city of Ashdod. At least 17 Israeli civilians have been treated for injuries from rocket attacks, the military said.

On Wednesday, Israel declared a state of emergency in the central city of Lod and dispatched border police battalions to the area for reinforcements, according to the government press office. The mixed Jewish-Arab city has seen protests escalate into riots this week.

A CNN team driving through Lod early Wednesday saw roads strewn with rocks and burned out cars. Overnight, a rocket hit a house in Dahamesh, just outside the city, killing a 52-year-old man and his daughter, both Israeli-Arab citizens.

The Israeli military said in a morning briefing on Wednesday that a total of five Israeli civilians have now been killed since the start of the violent exchange of rocket fire and airstrikes between Gaza and Israel earlier this week.

A 13-story tower block in Gaza city collapsed on Tuesday night after it was hit by an Israeli airstrike, drawing vows of retaliation from Gaza fighters.

The Israel Defense Forces (IDF) said in a statement that the building contained offices used by Hamas across several floors, including intelligence offices of its military wing, and a research and development unit working on rockets.

The IDF also said it provided "advance warning to civilians in the building and provided sufficient time for them to evacuate the site."

There are reports that one person on a nearby street was injured in the building's collapse.

Separately, in the early hours of Wednesday, two separate buildings were hit, a three-floor residential building in which three people were killed, Gaza health officials said, and a 10-story building which suffered major damage but saw no fatalities. The larger building, known as the al-Jawahera building, houses media network companies and other offices.

Following the Israeli strike on the tower, a barrage of more than 200 rockets was then fired from Gaza into Israel.

Earlier Hamas had warned if residential tower buildings in Gaza were targeted, they would not sit idle and would respond with rocket fire.

The Izz ad-Din Al-Qassam Brigades, the military wing of Hamas, says it responded with 210 rockets fired toward Beer Sheva and Tel Aviv.

Palestinian Ministry of Health spokesman in Gaza Ashraf Al-Qidra, said many Gaza residents are now in a state of panic due to the ongoing Israeli airstrikes.

"The deliberate targeting of civilian houses and crowded residential neighborhoods puts more than half of the population of the Gaza Strip, including women and children, in a state of panic," Al-Qidra said in a post to Twitter on Wednesday.

He said the ongoing Israeli airstrikes have "dangerous psychological repercussions due to frightening and successive sounds of explosions, scenes of destruction and victims."

Al Qidra also said 43 percent of the victims in Gaza are children and women.

Gaza's Interior Ministry's spokesman Iyad Al-Bazam also said in a statement released on Wednesday that dozens of Israeli airstrikes hit several areas in Gaza. Most airstrikes hit Gaza City and Khan Yunis in the southern portion of Gaza.

In the past two days, Hamas and Islamic Jihad in Gaza have fired at least 500 rockets into Israel, forcing the closure of Israel's main international airport, Ben Gurion, about fifteen kilometers east of Tel Aviv.

The fighters say it is a response to the actions of Israeli police who fired stun grenades inside the Aqsa Mosque in Jerusalem — one of the city's holiest sites — on Monday morning.

Hundreds of Palestinians went to hospitals for treatment after ensuing clashes with Israeli police, in the most serious violence seen in the city in weeks.

"We have the right to respond to the Israeli offensive and protect the interests of our people as long as the Israeli occupation continues the escalation," Hamas said in a statement.

The Israeli military has conducted more than 150 strikes in Gaza as of Tuesday afternoon, according to a military spokesman, who said Israel had also called up 5,000 reserve troops to active duty to "enhance" its operation in Gaza.

A number of deaths were reported in strikes in Beit Hanoun in northern Gaza. Among them were Amira Abdel-Fattah, 57, who was killed in her apartment along with her son who has special needs, Ibrahim Al-Masri, 11, and his brother Marwan, 7, the Palestinian health ministry said. The Israeli army says it is investigating.

A Palestinian man in Gaza told CNN over the phone that the sounds of Israeli strikes throughout Monday night, as well as the sound of outgoing rocket fire, had been "horrifying."

The man, who declined to be named, described a mood of anger in Gaza over recent events in Jerusalem. "It's the fact the Israelis targeted Al Aqsa, during Ramadan, while people were praying" that has so riled people, he said.

The man added that Israel's actions would only embolden support for Hamas, and that he believed fighters should continue firing rockets. — CNN