GAZA, Nov. 28 (Xinhua) -- The Israeli army on Sunday shot and wounded four Palestinians who were digging for gravel in northern Gaza Strip, a medical official said.

Adham Abu Selmia of the medical services said that the four workers were moderately injured. A spokesman of the Israeli army said that the four approached the security fence that separates Israel and Gaza.

The shooting took place near Erez crossing point and the Israeli authorities shut the passengers' gate briefly.

Meanwhile, Palestinian militants fired a home-made missile into southern Israel, causing no damage or casualties, Israel Radio reported.

On Saturday, three workers who were collecting gravel also got injured in northern Gaza. The Palestinians use the gravel in building to break away the Israeli sanctions that bar the entry of gravel and other construction materials.

Israel imposed a 300-meter-wide buffer zone along its borders with the Hamas-controlled Gaza Strip. Since February, 74 Palestinians have been injured inside the no-go zone.