International efforts to finalise a ceasefire are being stepped up after a night of renewed Israeli air strikes in Gaza and sporadic Hamas rocket attacks.
US Secretary of State Hillary Clinton is visiting the West Bank and, later, Cairo after talks with Israeli leaders.
Palestinian sources had suggested a truce would be announced on Tuesday, but Israel said no deal was struck.
Some 136 Palestinians and five Israelis have been killed since the flare-up began eight days ago, officials say.
On Tuesday alone, the conflict claimed the lives of at least 20 Palestinians and two Israelis.
Mrs Clinton has arrived in Ramallah on the West Bank for talks with Palestinian Authority President Mahmoud Abbas. UN Secretary General Ban Ki-moon is also visiting leaders in the region to try to cement a ceasefire.
In Cairo, officials from Hamas, the militant Palestinian group that has governed Gaza since 2007, had suggested a truce would come into effect at midnight on Tuesday, but Israel later said it had not agreed to a text.
Israel’s demands include no hostile fire of any kind from Gaza and international efforts to prevent Hamas from re-arming, while Hamas is demanding an end to the blockade on Gaza and targeted killings by Israel.
An Israeli official told Israel Radio the ceasefire had not been agreed because of “a last-minute delay in the understandings between Hamas and Israel”.
Offices struck
In the early hours of Wednesday, BBC correspondents in Gaza reported hearing loud explosions that were followed by a widespread power cut.
Israeli missiles struck the main complex of the Hamas-run government in the centre of Gaza City.
The BBC’s Paul Danahar in Gaza said the huge compound had been laid to waste and was little more than dust and rubble.
The Israeli military later tweeted it had “surgically targeted a Hamas intelligence operations centre” on the seventh floor of a media building.
Israel’s military, the Israel Defense Forces (IDF), said it had attacked more than 100 “terror sites” in Gaza overnight “of which approximately 50 were underground rocket launchers”.
The health ministry in Gaza said 15 more people had been injured overnight.
Offices struck
In the early hours of Wednesday, BBC correspondents in Gaza reported hearing loud explosions that were followed by a widespread power cut.
Israeli missiles struck the main complex of the Hamas-run government in the centre of Gaza City.
The BBC’s Paul Danahar in Gaza said the huge compound had been laid to waste and was little more than dust and rubble.
The Israeli military later tweeted it had “surgically targeted a Hamas intelligence operations centre” on the seventh floor of a media building.
Israel’s military, the Israel Defense Forces (IDF), said it had attacked more than 100 “terror sites” in Gaza overnight “of which approximately 50 were underground rocket launchers”.
The health ministry in Gaza said 15 more people had been injured overnight.
BBc
