One of the two men arrested on Monday for taking part in a vandalism attack at the Negev's Avdat archeological park is the sole guard who was hired by the Nature and Parks Authority to protect the site, police announced on Tuesday. The two men are accused by police of causing widespread damage to the site, knocking down ancient columns and splattering paint and oil on ruins, in revenge for the demolition of several illegal Beduin structures by the state on Sunday. A Negev police spokesman said it was too soon to say what part the guard played - whether he took an active role in the vandalism or whether he turned a blind eye to it. "As far as we're concerned, he is a suspect in this crime," the spokesman added. The men's custody was extended by four days on Tuesday. "We intend to continue to investigate, and we may arrest more suspects in the future," the spokesman said. The two suspects have no fixed address as they reside in nomadic Beduin communities. They have denied the charged. Avdat, originally a 2,000-year-old Nabatean city, was later settled by the Byzantines, who built churches in the area. It was a declared a UNESCO world heritage site in 2005, and contains many archeological treasures, attracting tourists from Israel and abroad all year round. The site was reopened on Monday afternoon. hours after the attack, but the Nature and Parks Authority said it would take months for archeologists to reconstruct the damaged sections.