GAZA/JERUSALEM (Reuters) - Israel struck dozens of targets in the Gaza Strip before dawn on Saturday, the Israeli military said, and Palestinian militants fired their heaviest rocket salvoes across the border since August.
There were no casualties reported during the exchange of fire in Israel or Gaza, which is controlled by the Islamist Hamas group.
The Islamic Jihad, one of the other armed groups that operates in Gaza, said in a statement it had fired the rockets in response to Israel's killing of four Palestinian protesters on Friday near the border.
It said it would halt its fire if Israel did the same.
The Israeli military said it holds Hamas responsible for anything that happens in Gaza. It said its air force hit about 80 targets including a four-storey building used by Hamas as a headquarters, in response to more than 30 rockets launched into Israel.
There was no immediate comment from Hamas.
In Israel, warning sirens sounded through the night in the towns and communities near the Gaza border, sending residents of to bomb shelters. Some rockets were intercepted.
Explosions echoed through Gaza, where militants usually vacate potential targets when violence flares, as buildings shook and flames lit up the night sky.
The flare-up began after the four Palestinians were killed by Israeli troops on Friday during weekly protests along the border. Israel said its forces were attacked with grenades and explosive devices hurled by some of the protesters, some of whom breached the border. [nL8N1X66GJ]
Palestinians have been protesting along the frontier since March 30, demanding an end to Israel's blockade of the territory and the right to return to lands from which they fled or were driven from when Israel was founded in 1948.
According to the Palestinian Health Ministry, 213 Gazans have been killed by Israeli forces during the protests. An Israeli soldier was killed by a Palestinian sniper.
Egyptian security officials have been talking separately to Israeli and Palestinian leaders in an attempt to restore calm along the border.
About two million Palestinians are packed into the Gaza Strip which is in a deep economic crisis, stricken by poverty and high unemployment.
Israel says it keeps a naval blockade and tight control of its crossings with the enclave for security reasons, to prevent weapons from reaching militant groups there.
(Reporting by Nidal al-Mughrabi and Maayan Lubell; editing by John Stonestreet)