Ansar al-Sunna, a previously unknown Palestinian armed group in Gaza, claimed responsibility for the March 18 attack which killed Manee Singmueangphon, a 33-year-old migrant Thai who worked in a commercial greenhouse in Netiv Ha'asara, 437 yards north of the Gaza Strip, Human Rights Watch reported Friday.
"Hamas as the de facto authority in Gaza has the responsibility to stop indiscriminate rocket attacks into Israel," said Joe Stork, deputy Middle East director at Human Rights Watch.
"The failure to bring justice for laws of war violations by both sides is fueling the suffering of civilians in Israel and Gaza."
Armed groups in Gaza have fired approximately 147 rockets into Israel since the end of major Israeli military operations in Gaza on Jan. 18, 2009, Human Rights Watch says.
After firing, the rockets land indiscriminately at populated areas because they lack any guidance mechanism and cannot be aimed accurately at military targets.
Israeli forces hit at least four targets in Gaza Friday in retaliation for this week's rocket attacks on Israel, a government official said.
Palestinians reported that two people were slightly injured in the strikes aimed at a smuggling tunnel, a metal foundry and two open areas, Ynetnews reported.
Deputy Defense Minister Matan Vilnai said Israel is holding Hamas accountable for all rockets that originate from Gaza.
Thursday, a foreign worker was killed in a rocket strike at Netiv Ha'asara.