JERUSALEM - US Secretary of State John Kerry will meet Israeli and Palestinian leaders Friday as he pushes a framework for Middle East peace talks, amid growing tension on the ground.
Kerry arrived in Israel Thursday and held talks with Prime Minister Benjamin Netanyahu, launching what is expected to be an intense four days of shuttle diplomacy between Israeli and Palestinian leaders.
Early Friday the problems involved were amply illustrated as Israeli war planes carried out a series of strikes in the Gaza Strip, shortly after a rocket from the Palestinian enclave struck the Jewish state.
A statement from the army said that "in response to rocket fire toward Israel", its "aircraft targeted a terror infrastructure site in the central Gaza Strip and three concealed rocket launchers in the northern Gaza Strip".
There were no immediate reports of injuries in Gaza.
Late Thursday night a projectile fired from the Islamist Hamas-run enclave hit southern Israel, a police spokeswoman told AFP, causing no harm or damage.
Kerry's initial meeting with Netanyahu, which included a joint dinner, lasted five hours, officials said.
The top US diplomat was due to meet his Israeli counterpart Avigdor Lieberman Friday morning before meeting again with Netanyahu, then heading to the West Bank city of Ramallah for talks with Palestinian President Mahmud Abbas.
Kerry has faced fierce opposition from both sides to any compromise on mostly irreconcilable demands since he kick-started direct negotiations in July after a three-year hiatus.
His latest visit, the 10th since March, comes with Palestinian and Israeli leaders accusing each other of lacking serious commitment to achieving a lasting peace.
"I plan to work with both sides more intensely in these next days to narrow the differences on a framework that will provide the agreed guidelines for permanent status negotiations," Kerry told reporters before meeting Netanyahu.
"An agreed framework would be a significant breakthrough."
Netanyahu repeated that he did not believe the Palestinians were taking the process seriously.
"A few days ago in Ramallah, president Abbas embraced terrorists as heroes... How can he say that he stands against terrorism?" he said.
Netanyahu was referring to Israel's release of the third of four batches of 104 veteran Palestinian prisoners as a goodwill gesture agreed under the talks process.
The Shin Bet, Israel's internal security agency, announced it had recently arrested four Palestinians who were involved in the December 22 bombing of a bus near Tel Aviv, in which a police sapper was lightly wounded.
According to a statement, the four were members of the Islamic Jihad from Bethlehem, one of whom has a brother who serves in the Palestinian Authority security forces. The Shin Bet said 10 others involved in the cell's activity were apprehended.
Netanyahu said in a statement the arrests were proof of "direct involvement of PA people in terror. It is time (Abbas) ceases celebrating with terrorists, and leads his people to peace".
As the Kerry met Netanyahu Thursday night dozens of Israelis were protesting outside the US diplomat's hotel for the release of Israeli spy Jonathan Pollard, a former US Navy analyst detained in 1985 for supplying Israel with secret documents and imprisoned in the US since.
A State Department official said ahead of Kerry's trip that he aims to hammer out a framework to guide the sides through the tough final months of talks, due to end in late April.
Kerry and his team hope to have the framework in place soon, addressing the core issues.
These include the contours of the borders of a future Palestinian state, the fate of Jerusalem which both sides claim as their capital, and Palestinian refugees.
The Palestinians want borders based on the 1967 lines that existed before the Six-Day War, when Israel captured the West Bank, including now annexed Arab east Jerusalem.
But Israel wants to retain existing settlements it has built inside occupied Palestinian territory since then.
Jordan Valley security
On security, Israel wants to maintain a military presence in the Jordan Valley, where the West Bank borders Jordan, under any peace deal.
The Palestinians reject this, instead seeking an international force to guarantee security there.
The latest prisoner release was expected to be followed by announcements of further Israeli settlement expansion on Palestinian territory, an issue that has crippled the talks and caused international anger.
A US State Department official said before the visit that Israeli settlement expansion had created difficulties, and reiterated Washington's position that the settlements are illegitimate.
Several thousand new settler homes, the building of which is illegal under international law, have been announced since the talks started.
The Palestinians have threatened to sue Israel through the international courts should it continue to expand its settlements.
But Abbas has also reiterated a commitment to see out the nine months of talks before taking such action.
The recent spike in exchanges of fire between the sides peaked last Tuesday, when a sniper inside Gaza killed an Israeli repairing the border fence.
Israel retaliated against "terror sites" in Gaza with warplanes and tanks, killing a toddler and wounding at least six people.