JERUSALEM (AP) -- Israel's military prosecutor dropped a manslaughter charge against a soldier initially suspected of killing a Palestinian woman and her daughter during Israel's war against Gaza militants nearly four years ago, a defense attorney said Sunday.

The former infantry sergeant was the only soldier facing such a charge stemming from an offensive that killed some 1,400 Palestinians, including hundreds of civilians, and 13 Israelis, according to the Israeli rights group B'Tselem.

Israel launched the war to stop daily rocket barrages by Hamas and other Palestinian militants at southern Israel, disrupting life there for months. Since the war, rocket fire has diminished considerably.

B'Tselem and other groups have called for independent investigations of what they said were dozens of suspected unlawful killings during the war. Instead, the military launched its own investigation into some of the deaths.

The infantry sergeant, who was initially charged with manslaughter, was convicted in an Israeli military court Sunday of illegal weapons use as part of a plea deal and will serve 45 days in prison, said his attorney, Oded Savoray.

The military confirmed Sunday that the charge had been reduced to illegal weapons use but gave no further details.

Savoray said his client fired a weapon without permission, but prosecutors did not present evidence he killed anyone. The sergeant and his unit were deployed in Gaza City's Zeitoun neighborhood during the first week of January 2009, several days after the start of the three-week offensive.

In July 2010, that military said the prosecutor was indicting the sergeant for manslaughter in connection with a Jan. 4, 2009, incident in which the two Palestinian women, 37-year-old Majda Abu Hajaj and her mother, 64-year-old Raya Abu Hajaj, were killed. The women were among dozens of civilians running from fighting when they came under fire from an Israeli tank, according to B'Tselem. Witnesses said they were holding a flag.

The military said there were discrepancies between the troops' accounts of the incident and the details reported widely by human rights groups. The troops reported shooting one man at the site, not two women, and on a different date.

In the end, the sergeant was charged with manslaughter, but no victims were named in the indictment, said Savoray. The sergeant could have faced 20 years in prison if convicted of manslaughter.

B'Tselem said the indictment was based solely on the soldiers' accounts and not on conflicting testimony from Palestinian witnesses.

B'Tselem had urged the military to open criminal investigations into 20 cases involving the killings of 92 Palestinians, including the mother and daughter from Gaza City, said B'Tselem spokeswoman Sarit Michaeli.

In 11 cases, investigations were launched. The sergeant was the only one so far to be charged in a killing.

A nephew of the two women, 45-year-old Mohammed Abu Hajaj, said the plea bargain is a sign Israel's military courts are not impartial. "The whole world knows what happened (during the Gaza war) and the whole world witnessed the crime against civilians," he said.