Four children, three senior Islamic Jihad commanders were among 12 people killed in Gaza airstrikes launched by the Israeli military on Tuesday in what it claimed was an attempt to target the Islamic Jihad group. The air strikes were the latest incident in more than a year of surging violence that has seen repeated Israeli military raids and escalating settler violence in the occupied West Bank, amid a spate of Palestinian street attacks on Israelis. Last week brought a bout of cross-border fire after the death in Israeli detention of a hunger striker from Islamic Jihad. Israel’s military said it targeted three senior commanders of Islamic Jihad, the second most powerful armed group in the blockaded coastal enclave, which is controlled by Hamas. “Any terrorist who harms Israeli citizens will be made to regret it,” said Defence Minister Yoav Gallant. Israel’s military, working with the Shin Bet intelligence service, targeted the leadership of the Islamic Jihad in Gaza in a “precise” operation, he added. The military said 40 jets took part in the strikes, which it said were timed to suit operational conditions. “It was a convergence of intelligence, timing and weather,” a military spokesperson said. A Gaza health official said at least 12 people had been killed and 20 wounded in the strikes that hit residential areas in the densely populated strip in which 2.3 million Palestinians live on a patch of 365 square kilometres (140 square miles). An Israeli military spokesman said the army was looking into reports of civilian deaths but had no immediate comment. “We’re aware of some collateral and we’ll learn more as the day goes ahead,” he told a briefing with reporters. Islamic Jihad’s armed wing confirmed the deaths of the three commanders, adding: “We will not abandon our positions and the resistance will continue, God willing.” The group identified the commanders killed as Jihad Ghannam, Khalil Al-Bahtini and Tareq Izzeldeen. The military said it targeted 10 weapon and infrastructure manufacturing sites, including rocket production workshops and a site for making concrete used for tunnels, as well as military compounds belonging to the group. As morning broke over Gaza, Israeli military spokesperson Daniel Hagari said the military had achieved its objectives and army chiefs and Shin Bet officials were holding assessments. The military said Gallant had approved drafting reservists while Palestinian groups said they would respond to the strikes, highlighting the potential for more prolonged hostilities. “The bombardment will be met by bombardment and the attack will be met by an attack,” said Tareq Selmi, a spokesman of Islamic Jihad. “This crime will not pass unpunished.” Hamas chief Ismail Haniyeh, who has been splitting his time between Turkey and Qatar, said in a statement: “Assassination of leaders will not bring the occupation security but more resistance.” Videos showed billowing smoke and flames that lit up the night sky as trucks of firefighters sped to a building that had been hit, while a medic reassured a young girl who appeared confused. “Your family is all safe, don’t worry,” he said. During the bombardment, Palestinians took to social media to mourn a well-known dentist who was killed at home with his wife in Tuesday’s air strikes, describing him as a loyal friend and humble man. Last week, the death of Khader Adnan in Israeli custody following an 87-day hunger strike triggered several hours of cross-border fighting between Israel and armed groups in Gaza, in which one Palestinian man was killed. More than 100 Palestinians and at least 19 Israelis and foreigners have been killed in the strife since January. The Palestinian foreign ministry strongly condemned Israel’s attack and said a negotiated political solution was the only way to achieve security and stability. Israel captured Gaza and the West Bank, areas where Palestinians aim to establish an independent state with East Jerusalem as its capital, in a 1967 war. COGAT, a unit of the Israeli defence ministry that coordinates civilian affairs with Palestinians in occupied territories, said its two Gaza crossings were closed to people and goods until further notice. In anticipation of rocket fire in response to the killings, Israel’s military urged citizens living in towns within 40 km (25 miles) of Gaza to stay near bomb shelters from 2:30 am on Tuesday until 6 pm on Thursday.