Jerusalem (CNN) -- Eleven rockets were fired into Israel from Gaza on Thursday, a day after a fatal terrorist bombing in Jerusalem killed a woman and wounded more than 50 other people, the Israel Defense Forces said. "The question is why," Brig. Gen. Yossi Kuperwasser said in a phone call Thursday, speaking about the increase in attacks, which the IDF said caused no injuries. Israel's ambassador to the United States said Thursday the rocket attacks appear "unrelated" to Wednesday's bombing in Jerusalem. Michael Oren said the rocket attacks probably have to do with infighting in the Hamas-controlled territory of Gaza. However, he said, there has also been an escalation in violence against his country.
@highlight
NEW: Eleven rockets were fired into Israel from Gaza on Thursday
@highlight
NEW: Israel launches airstrikes Thursday night in Gaza
@highlight
NEW: Obama expresses his condolences over the bombing
@highlight
Israel's U.S. ambassador says the bombing and rockets appear unrelated
A Hamas building and a @placeholder training camp were hit, he reported.