GAZA CITY (Ma'an) -- The search for a missing tunnel worker in Gaza continued on Saturday, relatives said.

Relatives of Bassam Khader told Ma'an that he has been missing now for four days, after last being seen working in a smuggling tunnel in Rafah.

Khalil, his brother, said that the family have looked for him since a tunnel he was working in collapsed due to severe weather conditions.

The family called on Gaza prime minister Ismail Haniyeh to intervene and send rescue crews to help find him.

On Friday, civil defense crews said that two workers were trapped in smuggling tunnels after heavy rain caused several underground passages to collapse.

An Egyptian official said this week that many of the tunnels under Gaza's border with Egypt have flooded or collapsed due to heavy rainfall.

The tunnel network developed as a vital source of goods under Israel's blockade of the coastal strip and Egyptian restrictions on the official Rafah crossing point.