JERUSALEM — The Israeli military announced Wednesday that it had closed its investigation into the 2009 deaths of at least 21 members of an extended Palestinian family who were huddled in a house that was struck by Israeli shells or missiles during the Gaza war, and that no legal steps would be taken against any soldiers involved.

Up to 1,400 Palestinians and 13 Israelis were killed during Israel’s three-week offensive against Hamas in Gaza in the winter of 2008-9, which came after years of rocket fire into southern Israel by Gaza militants. But the case of the Samouni family stirred particular horror and outrage around the world as Israeli forces prevented Palestinian paramedics from reaching the house for days after the strike. Up to 30 Samounis died in the house in the Zeitoun district of eastern Gaza City, where about 100 family members had gathered, according to witnesses at the time.

In a letter to local human rights groups that had pressed the case, the military advocate general’s office said the military police inquiry had refuted charges that Israeli forces had deliberately attacked civilians, or had acted hastily or recklessly. Survivors said they had been directed to the house by soldiers who were taking over the neighborhood.

The military did not offer a detailed explanation of what led to the strike on the house, but said that the nature of fighting in such a densely populated urban environment and the firing of a rocket- propelled grenade at the forces shortly before the episode contributed to the decisions taken by the area commander. While some mistakes were made, according to the military, the commander’s decisions were reasonable under the circumstances.

A scathing United Nations report published months after the war pointed to evidence of possible war crimes, but its principal author, Richard Goldstone, a South African judge, later retracted the assertion that Israel had deliberately killed Palestinian civilians during the fighting.

The Palestinian Center for Human Rights, which is based in Gaza, called the decision to close the case without any prosecutions “disgraceful.” The group says it has filed criminal and civil complaints on behalf of 62 victims of the Samouni killings.

The Israeli human rights group Btselem said that the army’s decision to clear itself of responsibility in the case showed the need for an Israeli investigator outside the army to look into its actions. (Copyright 2012 The New York Times Company 05/03/12)