Egypt has announced a cease-fire agreement between Israel and Hamas.
The cease-fire was scheduled to take effect at 9 p.m. (Noon MT) , Egypt's Foreign Minister Mohamed Kamel Amr said.
The announcement came hours after a bomb exploded on a bus in Tel Aviv.
The attack, which police said left 24 passengers injured, shook up the Israeli public and threatened to complicate efforts to achieve a cease-fire on the eighth day of violence between Israel and Gaza.
The bus attack left three people hospitalized in serious condition, police spokesman Mickey Rosenfeld said.
Hamas praised the attack but did not claim responsibility.
"We told you #IDF that our blessed hands will reach your leaders and soldiers wherever they are," the al Qassam Brigades, the military wing of Hamas, said on Twitter. "You opened the Gates of Hell on Yourselves."
Meanwhile, overnight and into Wednesday, Israeli bombs and artillery turned buildings, tunnels and bridges in Gaza into rubble in 100 strikes confirmed by Israeli authorities. At the same time, Hamas media boasted about their militants' rockets hissing off in the direction of populated areas of southern Israel.
U.S. Secretary of State Hillary Clinton shuttled from meetings with Palestinians to Israeli leadership Wednesday.
"Today the situation in Gaza is deeply alarming," U.N. Secretary-General Ban Ki-moon said.
"Rockets aimed at military targets inside Gaza are killing and injuring civilians and damaging... civilian infrastructures," Ban said.
He demanded that diplomacy pave the way forward and called for the emergence of a Palestinian state.
Israeli television showed images of white smoke rising up from the bombed public transportation bus in Tel Aviv, but from the outside the vehicle appeared intact. At least one passenger was taken out on a stretcher.
There is a hospital nearby, said CNN's Sara Sidner. An eyewitness told her that the windows of the bus were shattered and a bomb squad has approached it.
No one was found dead on the bus, according to authorities. Two people, speaking live on Israeli radio, said they witnessed the attack and that they saw a male throw a bag into the bus and then run away after the explosion.
Israel's Channel 10 reported that one suspect had been apprehended.
Hamas put its own spin on the attack in a banner on al-Aqsa.
"Hamas blesses the suicide bombing and assures that it is a natural response to the massacre of the al-Dalou family and targeting of innocent Palestinian civilians."
A rocket alarm howled over Ashkelon on the Israeli side shortly after 7:30 a.m. Wednesday, just minutes after Hamas' TV broadcaster al-Aqsa reported its militants' rockets striking there as well as in the towns of Sderot and Ashdod.
Since midnight, 17 rockets out of Gaza have touched down in Israel, the IDF confirmed. The Iron Dome protection system intercepted 12 more.
CNN's Fred Pleitgen in Ashkelon heard two impacts but could not yet say if the rockets hit anything or were eliminated mid-air by the rocket defense system.
The Israel Defense Forces overnight targeted "dozens of terror infrastructure sites," including the Ministry of Internal Security, which it saw as Hamas' "main command and control center." It took aim at a police compound, a "military hideout," and other targets linked to what it called Hamas' "terror activity."
The Israeli military also struck a media building, where it said Hamas "deliberately located" an "intelligence operation center," and a system of tunnels used to transport fuel.
Al-Aqsa said two of their journalists were killed when an Israeli strike targeted their car. The IDF confirmed the strike but said the two killed were Hamas operatives. Residents participated in a public funeral for the two.
The IDF also confirmed targeting bridges in central Gaza.
Gazan authorities have reported at least 139 people killed in the conflict as of Wednesday. Israel reported a total of five Israelis killed as of Tuesday.
According to the Gaza Ministry of Health, 27 people were killed Tuesday, including children. More than 1,100 people have been injured. It's not clear how many of the victims were militants.
More than 70 people have been injured in Israel, including soldiers, Israeli officials have said.