Israeli forces carried out air strikes in Gaza early on Thursday hours after a rocket was fired from the blockaded Palestinian territory.
The rocket, which reportedly triggered sirens in Sderot, Ivim and Nir Am, was intercepted by Israeli air defence system, the military said.
In response, Israeli fighter jets hit "a production site for raw chemical material production, preservation and storage along with a weapon manufacturing site" belonging to Hamas.
Security sources and witnesses in Gaza told AFP there were at least seven strikes on a training centre of the Ezzedine Al Qassam Brigades, the armed wing of Hamas, in the Al Maghazi refugee camp in the central Gaza Strip.
Another round of air strikes hit the Brigades' training centre south-west of Gaza City.
The strikes were followed by more rocket launches from Gaza, witnesses said.
The Democratic Front for the Liberation of Palestine said it launched rocket salvos at Israel in response to the air strikes and the "systematic aggression" against Palestinian prisoners in Israeli jails.
There were no immediate reports of casualties.
The attacks come a day after US Secretary of State Antony Blinken called for calm during a visit to the region.
There was cross-border rocket fire from the Gaza Strip last week in retaliation for a deadly Israeli raid in the occupied West Bank.
That was followed by a shooting attack outside a synagogue in occupied East Jerusalem on Friday, which killed seven civilians.
The attack on the Jewish Sabbath was the deadliest against Israeli civilians in more than a decade.
Last week, Israeli forces killed 10 people the Jenin refugee camp in their worst raid in the West Bank in nearly two decades. Israel said Islamic Jihad militants were the target of the operation.
Antony Blinken's Middle East Tour — in pictures
Hamas, which controls Gaza, and Islamic Jihad both fired rockets at Israel after Thursday's raid.
Israel then hit Gaza with retaliatory air strikes, and the Palestinian groups vowed further action.
Mr Blinken left the region late on Tuesday after meeting Israeli and Palestinian leaders.
The top US diplomat had urged both sides to take "urgent steps" to restore calm.
Washington has no contact with Hamas, which it considers to be a terrorist organisation.
The Islamic Jihad said it would send a delegation led by the militant group's leader, Ziad Al Nakhala, to Cairo on Thursday at Egypt's invitation.
The delegation would meet the head of Egypt's intelligence service to discuss "how to restore calm, especially after the last escalation, including the aggressions against prisoners", said Daoud Shihab, a senior Islamic Jihad member in Gaza.
Israel swears in new right-wing government — in pictures
The escalating violence has affected much of the West Bank, including Jericho, a tourist destination near Jerusalem that has remained largely peaceful in recent years.
The regional Palestinian governor on Wednesday accused Israel of putting the area under "siege" after a shooting at a restaurant on Saturday that resulted in no casualties.
"This is the fifth day of the siege on Jericho," Governor Jihad Abu Al Assal told AFP.
Israel's army told AFP it had boosted its numbers in the area and "inspections were increased at the city's entrances and exits" after "a shooting attack".
Cars were backed up at entrances to the city, with checks to get in and out of the city often taking hours, AFP reported.
In January, Israeli forces killed 35 Palestinians, including attackers, militants and civilians, while the Friday attack in East Jerusalem killed six Israelis, including a child, and one Ukrainian.
Blinken meets Israel's Defence Minister before heading to West Bank — video
Blinken meets Israel's Defence Minister before heading to West Bank
Israel has occupied the West Bank since 1967.
About 235 people died in the Israeli-Palestinian conflict last year, with nearly 90 per cent of the fatalities on the Palestinian side, AFP figures show.
The year 2022 was the deadliest in the West Bank since the UN started tracking fatalities in the occupied territory in 2005.
At the end of his three-day visit, Mr Blinken said he was leaving senior staff behind in the region, hoping to implement "constructive ideas" to stem the fighting, but declined to detail what measures might be advanced.
He warned that Palestinians face "a shrinking horizon of hope, not an expanding one", in a trajectory he said needed to change for the conflict to ease over the long term.
