Human Rights Watch says Israel unlawfully killed at least 29 civilians using missiles fired from drones during its three-week offensive in the Gaza Strip.

Palestinian children search in the rubble of a house, destroyed in the Israeli military offensive in Gaza, in the Rafah refugee camp, southern Gaza Strip, Sunday, 28 June 2009

The New York-based rights group released a report Tuesday accusing Israeli forces of failing to take all feasible precautions to verify the targets were combatants, despite having advanced surveillance equipment.

Israel's military issued a statement casting doubt on the validity of the report.  Officials say Israel complied with international law and did not target civilians.

Human Rights Watch says children were among those killed in six different drone missile strikes on targets that include a bus station and a school serving as a refugee center in Gaza.

Israel's offensive was aimed at stopping rocket attacks from the militant group Hamas.  At least 1,300 Palestinians and 13 Israelis were killed in the conflict that ended in January.

Separately, the Israeli navy ordered a small ship carrying humanitarian aid to Gaza to turn back Tuesday.  

Organizers of the group, Free Gaza Movement, said the vessel left Cyprus bound for the Palestinian territory with 21 activists on board.  The group has been intercepted twice before but made five successful missions to Gaza since last year, in defiance of an Israeli blockade on the territory.

And a Spanish court on Tuesday dropped a probe targeting Israeli officials for alleged crimes against humanity in connection with a 2002 Israeli air strike that killed a suspected Hamas militant and more than a dozen others in Gaza.

The court decided to close the probe by Spanish judge Fernando Andreu as recommended by prosecutors on the basis that Israel already was investigating the attack.

The judge agreed to look into the air strike at the request of a Palestinian rights group under Spain's observance of universal jurisdiction.  Under the principle, alleged cases of genocide, terrorism or crimes against humanity can be prosecuted in Spain, even if they are committed outside the country.

Some information for this report was provided by AFP, AP and Reuters.