Dozens of Bedouins 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 Bedouins, 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 Bedouins 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 Bedouins continued to block commercial traffic through Nitzana.