This woman and child were evacuated from a building in Gaza
Israel said it had killed senior Hamas officials in Gaza, and was also targeting missile launching sites. Hamas confirmed a senior commander and "other leaders" had died.
The Israel Defence Forces (IDF) said on Wednesday that their strikes on Gaza were the largest since the conflict in 2014.
Residents had been warned to evacuate the buildings before fighter jets attacked; however health officials said there were still civilian deaths.
Five members of one family were killed in an air strike on Tuesday, including two young brothers, according to AFP news agency.
"We were laughing and having fun when suddenly they began to bomb us. Everything around us caught fire," their 14-year-old cousin, Ibrahim, said, breaking down in tears as he described their death.
Meanwhile millions of Israelis were in bomb shelters on Wednesday evening, according to the IDF, after sirens warning of rockets sounded across the country.
Anna Ahronheim, the defence and security correspondent of the Jerusalem Post, described spending Tuesday night in a shelter with her five-month-old baby.
"To hear hundreds of interceptions and even to hear rockets fall near us was horrifying," she told the BBC.
A child killed in the Israeli town of Sderot was named as Ido Avigal, aged six, who was caught in an attack on a block of flats.