2 more women and a child killed in Gaza "work accident"

From JPost:

A powerful explosion went off in a house in southern Gaza on Saturday, killing two women and a four-year-old girl, Palestinian medics and witnesses said.

The cause of the blast in the town of Khan Yunis was not immediately clear.

The blast tore down the facade of the house and badly damaged its interior. A neighboring house was also partially damaged from the force of the blast.

The IDF said it was not carrying out any operations in the area at the time.

Hamas police said they suspected explosives being handled by militants went off prematurely.

Our 2007 count of Palestinian Arabs being violently killed by each other now climbs to 564.
UPDATE: From both Arab sources and YNet it looks like it was two children and an adult woman.
UPDATE 1A: PCHR says 2 18-year old women and one child, so I'm going with that.
UPDATE 2: Hamas blames Israel even though pretty much everyone knows that's BS.
UPDATE 3: Hamas member killed in Rafah by "unknown gunmen."565.