Israel's military operation against the Gaza Strip went on for a second day on Thursday with casualties reported on both sides as some Islamic nations voiced condemnation against the Jewish country.

The Palestinian enclave of Gaza came under fire Wednesday when Israel launched a series of airstrikes, which killed Islamic Hamas movement's armed wing commander Ahmed al-Jaabari, in response to Gaza militants' incessant rockets fired in to its southern part in the past few days.

The airstrikes marked the commencement of a military operation "Pillar of Defense," which aims to target Hamas' top leadership, as well as the organization's infrastructure in Gaza, including its stocks of rockets, training camps, rocket-launching sites and police stations.

The operation was met by Gaza militants' even more fierce rocket attacks towards Israel.

Ashraf al-Qedra, spokesman of the Hamas-run ministry of health, told reporters Thursday afternoon that since Wednesday afternoon, 13 Palestinians were killed and 145 injured.

Hamas said in a press statement emailed to reporters that seven of the 13 killed are civilians, including a pregnant woman, an 11- month-old child, a 3-year-old girl, a 65-year-old man and six Hamas militants (including al-Jaabari.)

The Islamic movement's armed wing, al-Qassam Brigades, said in a separate leaflets emailed to reporters that more than 250 short and long range rockets were fired on Israel; also, Hamas said Israeli warplanes carried out more than 90 airstrikes on various targets and militants all over the Gaza Strip.

In Israel, three civilians were killed and five others, including three soldiers, were wounded on Thursday. The three civilians, all from one family, died when a rocket hit their home in the city of Kiryat Malakhi, and the three soldiers are the first wounded military personnel since Israel launched the operation.

Moreover, A rocket from Gaza exploded near central Tel Aviv Thursday evening for the first time since the 1991 Gulf War, a witness near the point where the missile struck told Xinhua.

Also, Israeli politicians said they are suspending their election campaigns in light of the ongoing operation in the Gaza Strip.

Meanwhile, leaders of the Islamic countries in the region voiced solidarity with the Palestinians and condemnation against Israel amid the escalation of violence between the two sides.

On Wednesday, Egyptian President Mohamed Morsi decided to recall his ambassador to Israel in protest against the Jewish country's military operation in Gaza, while the Arab League announced an emergency meeting of foreign ministers to be held on Saturday to tackle the situation.

On Thursday, Jordanian government spokesman Samih Maaytah said "This hostile policy by Israel will drag the region into the cycle of violence and stability again."

"Israel's aggression will undermine the path towards a political settlement and will cause instability in the region," he added, stressing the need for an immediate halt of the aggression on the strip and protecting the Palestinians.

Iranian Foreign Ministry spokesman Ramin Mehmanparast asked the Non-Aligned Movement (NAM) member states to cut ties with Israel in light of the development and urged the international organizations and the human rights supporters to break "silence" on the attack.

Moroccan Ministry of Foreign Affairs issued a statement saying it "considers this dangerous escalation is unacceptable and that the continuation of these attacks could have disastrous consequences on the security and stability of the region."

At the General Conference of the Islamic Movement in Sudan, President Omar al-Bashir said "our brothers in Gaza are exposed to a heinous Zionist aggression" and "All Islamic nations are standing behind our brothers in Gaza."

Bashir's denouncement was echoed by Tunisian government who said, according to official TAP press agency, Israel's aggression "runs counter to all human rights and international conventions," and called on the international community "to compel Israel to cease hostilities against the unarmed Palestinian people."

Also, at a foreign minister meeting of the Organization of Islamic Cooperation (OIC) in Djibouti, Turkish Foreign Minister Ahmet Davutoglu said that Ankara will take steps at international institutions, including the OIC, for necessary measures against Israel for its "aggressive position" against Gaza.