Gaza, May 9 : Thirteen people, including three commanders of the Islamic Jihad militant group, were killed and 20 others injured in Israeli air strikes that pounded the Gaza Strip on Tuesday. Palestinian security officials in Gaza told Xinhua news agency that the airstrikes hit buildings, military facilities, and posts mainly in the towns of Rafah and Khan Younis in southern Gaza Strip and in Gaza City. An Israeli army spokesman said in a statement that the military launched the military operation "Shield and Arrow" against the Islamic Jihad in the Gaza Strip, which is ongoing. Confirming the development, the Islamic Jihad's military wing, the al-Quds Brigades, said three of its commanders were killed, along with their families. It identified them as Jihad Shaker al-Ghannam, secretary of the al-Quds Brigades' Military Council; Khalil Salah al-Bahtini, the commander of its Northern Region, and Tariq Muhammad Ezzedine, who it said was "one of the heads of military action" in the occupied West Bank. "As we mourn our martyr leaders, along with their mujahideen wives and a number of their children, we affirm that the blood of the martyrs will increase our resolve," the al-Quds Brigades said. "We will not leave our positions, and the resistance will continue, God willing." Israel Defense Forces spokesman Daniel Hagari said the three Islamic Jihad leaders who were killed in the operation were "an undermining factor for security stability". The Israeli army also said that according to an assessment of the situation, the military had ordered Israeli residents living close to the Gaza Strip to stay near bomb shelters at a distance of 40 km for fear of rocket fire from Gaza. Citing possible retaliatory rockets from Gaza, Israel suspended the train service in the southern cities near the besieged enclave. In many communities, local municipalities opened shelters, and Defence Minister Yoav Gallant authorised a call-up of reserve soldiers. The health ministry in Gaza said in a statement that the victims also includeded women and children. At least 20 other people were injured as the airstrikes hit the top floor of a residential building in Gaza City and a house in Rafah. The airstrikes came less than a week after over 100 rockets were fired from the Gaza Strip into southern Israel following the death of Islamic JIhad official Khader Adnan, who had been on hunger strike for 86 days while under Israeli custody. The Islamic Jihad is the biggest militant group next to Hamas in Gaza, reports the BBC. It has been responsible for many of the rocket attacks Israel from the territory in recent years and is sworn to Israel's destruction. /IANS