Benjamin Netanyahu has warned Israelis to brace for prolonged fighting as Palestinian factions in Gaza fired barrages of rockets in retaliation for Israel's assassination of a senior Islamic Jihad commander.

The most serious escalation in six months began early Tuesday when Israeli warplanes targeted Baha Abu al-Ata, the military commander of the Iranian-backed Islamic Jihad group in Gaza. The 42-year-old militant and his wife were both killed in the strike in Gaza City.

Mr Netanyahu called al-Ata “a ticking bomb” who was planning attacks against Israel “in the immediate short term”. “This arch-terrorist was the main instigator of terrorism from the Gaza Strip,” the prime minister said.

Soon after the raid in Gaza, a suspected Israeli airstrike targeted another senior Islamic Jihad leader at his home in Damascus, where the group is headquartered. The official was not home but his son and granddaughter were killed, according to Syrian state media. Israel’s military refused to say if it was behind the strike.

Islamic Jihad vowed it would go to war to avenge the attacks on its leaders and Palestinian factions quickly began filling the skies above southern Israel with rockets. The Israeli Defence Forces (IDF) said more than 150 rockets were fired over the course of Tuesday.