JERUSALEM, Aug. 9 (Xinhua) -- Israeli fighter jets struck Hamas military compound and tunnels in the Gaza Strip on Thursday, amid the second day of violent escalation between Israel and Hamas, officials said.

A military spokesperson said in a statement that military aircrafts struck "several military targets along the Gaza Strip."

The sites included a military compound belonging to Hamas' eastern Rafah Battalion, an offensive tunnel shaft located near Jabalia in northern Gaza Strip, and two Hamas combat tunnels adjacent to the beach in central Gaza, the spokesperson said.

The spokesperson warned that Israel will continue to attack combat tunnels, "until the current offensive threat of the enemy tunnels will end."

The widescale strikes in Gaza destroyed about 150 Hamas' "strategic military targets," said the spokesperson, adding that the assaults "delivered a severe blow to the organization's capabilities."

The military said it holds Hamas, the Palestinian Islamist movement that runs Gaza, accountable for any hostility coming from the besieged enclave.

"The Israel Defense Forces (IDF) is prepared for a range of scenarios and is determined to fulfill its mission of protecting Israeli civilians," the statement read.

The Palestinian Health Ministry said three people were killed in the attacks: Enas Khammash, a 23-year-old pregnant woman, her 18-month-old baby daughter Bayan and a Hamas fighter. At least 12 others were wounded.

Israeli prime minister's office said Prime Minister Benjamin Netanyahu has summoned an urgent meeting with Chief of General Staff Gadi Eizenkot and Defense Minister Avigdor Lieberman. The three are expected to discuss proposals for a cease-fire, according to a report on Kan TV news channel.

United Nations' Special Coordinator for the Middle East Peace Process, Nickolay Mladenov, said on Thursday that he works with Egypt to avoid further escalation.

"Our collective efforts have prevented the situation from exploding until now," he said in a statement, warning that "if the current escalation is not contained immediately, the situation can rapidly deteriorate with devastating consequences for all people."

The recent flare-up began on Wednesday evening, when Gaza militants fired rockets towards the southern Israeli city of Sderot, injuring about nine people.

Overall, more than 180 rockets have been launched toward southern Israel since Wednesday night, said IDF, adding that some 30 of them were intercepted by its Iron Dome rocket defense system and most of the others fell in open fields.

A total of 23 people in Israel were injured and needed a hospital care.

The rocket fire started after Israel killed two Hamas snipers in Gaza on Tuesday. Hamas vowed that Israel will pay a price for the killing.

It was the third serious flare-up of violence since July and came amidst attempts by UN's envoys and Egypt to broker a cease-fire between Israel and Hamas.