A tunnel used for smuggling arms from Egypt into the Gaza Strip (search) collapsed, trapping six Palestinians (search) inside, Palestinian witnesses and officials said Friday.

The tunnel is just four meters (yards) from the Egyptian border in the a-Salem neighborhood of the Rafah refugee camp (search). It collapsed late Thursday, but neighborhood residents only discovered the gaping hole that remained of the tunnel on Friday.

The Palestinians have requested permission to send rescue services into the area, which is not far from an Israeli outpost and off-limits to Palestinians. Bulldozers and ambulances are waiting to receive the OK from the army, Palestinian officials said.

Palestinians dig tunnels under the border to smuggle arms into the Gaza Strip.