Dozens of Beduin armed with rocket-propelled grenades ambushed Egyptian guards at the Nitzana border crossing with Israel on Tuesday, injuring two people, police said. One of the wounded was a police officer, and the other was a civilian who works at the checkpoint, an officer said on condition of anonymity because he was not authorized to speak to media. The Bedouin, their faces masked with traditional Arab scarves, also set fire to a police car and shot at the tires of trucks laden with goods, preventing them from crossing to Israel, police said. The attack escalated from a protest march opposing the arrest two days ago of two Beduin from the Tarabin tribe. The men were apparently arrested during a tribal dispute over a woman's honor, police said. By midday Tuesday, more than 50 Beduin continued to block commercial traffic through the Nitzana crossing, about 60 kilometers south of the main Egypt-Gaza crossing of Rafah. The account was corroborated by at least two police officials at the scene, who spoke on the same condition of anonymity. Egyptian reinforcements from farther north in El-Arish were en route to the scene.