The fighting in Gaza appeared to reach the Golan Heights on Sunday when gunshots were fired at an IDF vehicle along the border with Syria. It was the second attack along Israel's northern border since Operation Cast lead began in late December. The IDF said the vehicle was carrying civilians and soldiers who were conducitng engineering work along the border. No one was hurt, though the vehicle sustained some damage and military sources said it was likely a lone Syrian gunman who decided to open fire at the force to protest the IDF operations in the Gaza Strip. Shortly after the incident, Israel filed a complaint with UNDOF, the United Nations observer force based in the Golan Heights. Last Thursday, two people in a retirement home were lightly wounded when four Katyusha rockets slammed into the northern city of Nahariya. Hizbullah leader Sheikh Hassan Nasrallah said his organization was not behind the attack and military sources said it was likely carried out by Hizbullah. "We are keeping a close eye on the northern border," a senior defense official said Sunday. "The shooting from Syria appears to be a lone gunman but we are concerned with Hizbullah in Lebanon which might attack Israel to help Hamas in Gaza."