Four people were killed and three went missing in the collapse of an underground tunnel north of the Rafah border crossing between Gaza and Egypt, security sources said.
Sources from the militant group Hamas informed Egyptian authorities of the incident, dpa reports.
Egypt is still searching for the missing people inside the tunnel, the source said.
The identities of the dead and missing were not immediately known, the source said.
Four Palestinians were injured and hospitalized earlier Sunday after the collapse of another tunnel, according to Palestinian medical sources.
Tunnels on the Egyptian border have become common ways to get food and fuel into the Gaza Strip, which Israel blockaded after Hamas took over the coastal territory last year.
Israel has demanded that Egypt do more to prevent smuggling into Gaza, and Egypt publicizes its efforts to close the tunnels.