In the aftermath of a deadly rocket attack which killed two Israeli men and one woman on Thursday morning in a southern Israeli town, police sources said their deaths could have been avoided.

The Israeli Police Chief, Yohanan Danino, who visited the scene in Kiryat Malachi, said that if the victims would have managed to find shelter in time, they could have still been alive.

The sirens which alert the citizens of southern communities in Israel, called "tzeva adom" or code red, give citizens 45 seconds in advance to prepare for an incoming missile strike.

"If they would have just gone out to the staircase of the buildings, they would have been talking with you now instead of me, " the chief told journalists outside of the building.

Another police source said it appears as if the victims were about to head out to the staircase to find shelter there -- but did not make it on time.

Yedidyah Halevy, a volunteer for a forensics group called Zaka who lives nearby the struck building, told Xinhua what he had witnessed this morning.

"I live in the adjacent street to the building ... I heard an explosion and ran in the direction of the smoke ... very soon other Zaka and Magen David Adom (emergency services) got there and we tried to treat the injured who were at the top floor, but unfortunately we couldn't help them," he said.

Two people were injured in the strike, including a four-year old boy who was severely wounded. Doctors at the Tel Hashomer hospital near Tel Aviv managed to stabilize his condition. Another baby was injured lightly.

Other residents of the building have told the local website Ynet news that because the shelter was not prepared to take in people, they all prefer to stay in their homes.

This is the first deadly assault against Israeli citizens since "Operation Pillar of Defense" started on Wednesday afternoon. It is also one of the first attacks after a long period in which Israeli citizens die as a result of rocket attacks.

The large-scale military operation began as the Israeli Air Force (IAF) struck down the head of the Hamas' military wing, Ahmed al-Jaabari, and his son on Wednesday afternoon.

The operation has been focusing so far on air raids, and both Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak said that the military is ready, if necessary, to have ground forces invade the Gaza Strip.

The Israeli Defense Forces (IDF) is continuing to hit targets from the air in the Gaza Strip, announcing hitting 156 militant- related sites in the Gaza Strip, including caches of long-range missiles and other militant-related infrastructure.

According to Palestinian reports, there are 13 dead and dozens of wounded.

Meanwhile, nearly 200 rockets were fired from the Gaza Strip towards southern Israeli communities in the past 24 hours, including Be'er Sheva, Dimona (home to Israel's nuclear reactor), Ofakim and Sderot.

Another direct hit was reported in a house in Sderot. No one was there during the incident and no injuries were reported. However, a gas tank has been hit and is treated by the municipality employees.

The Iron Dome anti-missile battery managed to intercept 80 out of those rockets, according to data provided by the IDF spokesperson unit.

The Israeli Home Front command has called upon citizens living in communities within 40 km of the Gaza Strip to stay alert to instructions and stay close to a shelter. School is out in southern Israel because of the recent events, and citizens who live at a seven km distance from the strip have been asked to remain indoors until further notice.