Gaza City - Two Palestinians were killed Thursday when an underground tunnel dug for smuggling goods collapsed on them in the southern Gaza Strip, medical officials said.

Paramedics said they removed two dead bodies from the tunnel, which leads under the Gaza-Egypt border, to the east of the Rafah crossing. That crossing has been closed as part of economic sanctions on the Hamas-ruled Strip.

Two other people were injured and three others were missing, they said.

Officials at Abu Yousef al-Najjar hospital in Rafah said identified the dead as Mohammed Abdel Atti and Mahmoud Abu Dan, both in their twenties.

The latest deaths raises the number of the people killed in similar incidents this year to 18, the medical officials said.

Hundreds of tunnels are estimated to have been dug under the Gaza-Egypt border, with the number having increased after Israel sealed off commercial crossing points into Gaza in June 2007, when Hamas violently seized sole control of the Strip.

The tunnels are used to smuggle food, fuel and other goods, such as cigarettes. They are also used to smuggle weapons for armed Palestinian groups. (dpa)