Palestinian militants in Gaza have fired dozens of mortars at israel in the heaviest such barrage in years.
More than 30 were launched. Most were intercepted though one landed in the yard of a kindergarten, slightly wounding a worker.
israel responded with air strikes on militant positions in Gaza. There were no immediate reports of casualties.
The latest flare-up follows weeks of Israel-Gaza violence which has seen more than 100 Palestinians killed.
They were shot dead by Israeli snipers amid protests which saw thousands of Palestinians mass on the Gaza-Israel border in support of their refugee population.
Israel said its snipers had opened fire on attackers or people attempting to infiltrate under cover of protests, but UN and human right officials have accused Israel of using disproportionate force.
‘Forceful response'
Sirens warning of incoming fire rang out in Israeli communities around the Gaza Strip on and off on Monday.
The Israeli military said the biggest volley of mortar shells was fired at several sites in Israel in the early hours, with most intercepted by the Iron Dome anti-missile defence system.
Some mortars landed, included one in the grounds of a kindergarten in the Eshkol region, which borders Gaza, shortly before pupils were due to arrive.
More shells were launched in subsequent attacks, the Israel Defense Forces (IDF) said.