“The odor of blood in the hospital’s emergency room this morning was unbearable,” Karin Huster, a medical adviser for Doctors Without Borders in Gaza, said in a statement. “There are people lying everywhere, on the floor, outside.”

Israel’s military said it was conducting military operations “above and below ground” against Hamas militants in Bureij and the eastern part of Deir al-Balah, both in central Gaza, and that it had “eliminated” several.

Hamas also reported clashes with Israeli forces in the area, and said on Wednesday that it had fired missiles at Israeli troops in the east of Bureij.

“There is no place to flee to now,” said Hani Ahmed, a teacher and father of five who lives near the center of Bureij, and said two buildings in his area had been struck.

“Khan Younis is rubble. Rafah is under attack. The north is destroyed,” Mr. Ahmad said. “I might take my family in my small bus and live at the beach as I have no tent. We are terrified.”

As the bloodshed in Gaza continued, there was growing talk in Israel of going to war in Lebanon against Hezbollah militants, who have been trading strikes with Israeli forces for months, forcing more than 150,000 people on both sides of the border to flee.

Israeli military officials said this week that they were growing increasingly frustrated with Hezbollah’s attacks. On Wednesday, at least nine people were wounded after an explosive hit Hurfeish, a village in northern Israel, according to an Israeli hospital official.

“We are approaching the point in which a decision needs to be made, and the I.D.F. is ready and prepared for that decision,” Lt. Gen. Herzi Halevi, the Israeli military’s chief of staff, said on Tuesday.