JERUSALEM - At least two rockets were fired at Tel Aviv, Israel's economic and cultural hub, from the Gaza Strip Thursday evening as fighting escalated between Israel and Palestinian militants on the second day of Israel's large-scale military operation against Islamist group Hamas.

There are conflicting reports of whether the rockets landed within or near the city. Initial reports said a rocket exploded in a major intersection near downtown Tel Aviv. However, a police spokesman later said the rocket exploded off the shore of Bat Yam, south of Tel Aviv.

This is the first time in over 20 years that rockets reached so close to Israel's largest city. The last time was in the 1991 Gulf War.

The Israeli Defense Forces (IDF) spokesperson Yoav Mordechai confirmed the report at a press conference Thursday evening.

"According to what we know at present time, there were no rocket scrapes on the ground. No injuries or damages were reported, " he said.

The military's top brass had just finished convening, reviewing several operative options, he said, adding that this night will " not be quiet."

The Islamic Jihad militant group in Gaza claimed responsibility for the attack Thursday evening.

Two hours earlier, a siren went off in the area of Rishon Lezion, some 20 km south of Tel Aviv, for the first time during operation Pillar of Defense, which entered its second day.

Israel has been attacking targets in Gaza for the past 30 hours. On Wednesday afternoon, the Israeli Air Force targeted Hamas' military chief, Ahmed Jabri, and killed him.

According to the Palestinians, 15 have been killed so far and more than 40 wounded.

On the other hand, upwards of 250 rockets were launched toward Israel's southern communities in the past 24 hours. Three Israelis were killed Thursday morning when a rocket slammed into an apartment building in the southern city of Kiryat Malachi. In a separate incident, a rocket hit a military outpost in southern Israel, injuring three Israeli soldiers, one moderately and the two others lightly.

Both political and military officials underscored on Thursday that the option of a ground invasion into the strip "is on the table," and reiterated Israel would do whatever it takes to keep its citizens safe and damage the militants' infrastructure.