Israel bombed the Gaza Strip overnight, killing three senior commanders of the Palestinian Islamic Jihad group.
Various sites linked to the organization were also destroyed, including a rocket factory and a concrete production facility for the tunnels.
At least 12 people were killed and 20 injured, according to the latest figures from the Palestinian Health Ministry. Islamic Jihad says the dead also include the wives and some of the children of the three commanders.
An Israel Defense Forces (IDF) spokesman called the targets “pivotal terrorists” and said they were “aware of certain safeguards” in reference to civilian deaths.
Forty planes were used in the operation, which began just after 2 a.m. and was dubbed “Shield and Arrow”.
The strikes hit the top floor of an apartment building in Gaza City and a house in the southern town of Rafah
The IDF confirmed that the commanders killed were Khalil Bahitini, who led PIJ operations in northern Gaza, Tarek Azaldin who allegedly coordinated attacks in the West Bank from Gaza and Jahed Ahman, a senior member of the group’s military council.
Analysis by Alistair Bunkall
With 12 dead, including women and children, this is likely to degenerate.
The IDF says the strikes target only Palestinian Islamic Jihad, but steps already taken, including approving the evacuation of border towns, suggest they are ready for conflict.
The operation was approved by Israeli Prime Minister Benjamin Netanyahu last Friday, but was delayed once due to weather conditions and again when the targets were not in place. The strikes took everyone by surprise – as of breakfast time on Tuesday morning there was still no response from Islamic Jihad, but it is likely to come after the funeral later in the day.
The key to what happens next will be Hamas’ response. The group, which controls the Gaza Strip, issued a statement condemning the attacks but refrained from saying it would retaliate.
Last year, a similar operation against Islamic Jihad resulted in three days of fighting. On this occasion, Hamas chose to sit on the sidelines but may feel under pressure, particularly from Iran, to respond this time.
Mr Netanyahu has come under increasing pressure to adopt a more proactive counterterrorism policy, hitting the targets first rather than acting retrospectively. Right-wing voices within his government have argued for a more aggressive military posture in the West Bank and Gaza, and it appears to be exactly that.
The funeral is scheduled to take place Tuesday morning.
Israel is preparing for a response – schools near the Gaza border will be closed today, residents have been ordered to stay near bomb shelters and approval has been given for the evacuation of some towns.
Outdoor gatherings were banned and the Erez crossing between Gaza and Israel closed.
Reservists have been put on standby and Israel’s Home Command is ready for further action.
The strikes came as a surprise, and Islamic Jihad has yet to respond, but it follows a brief but intense 24-hour period last week when nearly three dozen rockets were fired at Israel after the death of a high profile Palestinian following a hunger strike in prison.