Israel turned to diplomacy to try to explain its operation in Gaza Thursday amid reports that a Hamas military commander was killed in an Israeli airstrike.

As its troops and tanks gathered along the Gaza border, positioning Israel for a ground invasion, Israeli Foreign Minister Tzipi Livni traveled to Paris for meetings with French leaders, who are looking for a way to implement a cease-fire, The New York Times (NYSE:NYT) reported. Livni said prior to her trip that her country wanted more time to carry out its military operation, which Israeli official say is intended to put an end to rocket attacks on Israel.

The Israeli government rejected a French proposal for a humanitarian truce Wednesday, with government spokesman Mark Regev saying a "real and sustainable solution" to attacks by Palestinian militants was needed.

Nizar Rayan was one of 10 people killed when an Israeli missile hit his house in the Jabalya Palestinian refugee camp north of Gaza, CNN reported. He was described by Israeli media as the most senior Hamas leader killed since the air assault began six days ago.

Palestinian medical sources told CNN 400 people have been killed in Gaza since the Israeli raids began Saturday, with 42 children, 13 women and two medical workers included in toll. Medical personnel said 2,000 people have been wounded, 216 of them critically.

Four Israelis, three of them civilians, have been killed and 56 wounded by Palestinian rocket fire, Israeli officials said.

Israeli airstrikes hit targets south, west and north of Gaza, Palestinian sources said, including legislative and ministry buildings and a civil defense headquarters. Israeli military officials said the air force and navy hit 20 targets overnight.

Meanwhile, five rockets were launched into Israel, including two medium-range rockets that fell near the Beersheva, military officials said.

Hamas Prime Minister Ismail Haniya, whose office in Gaza was hit Wednesday, said Israel must "stop attacking and killing our children, women and men."

U.N. ambassadors, meanwhile, met in emergency session to consider a draft resolution calling for an immediate cease-fire in Gaza. The United States indicated the resolution wasn't balanced enough.