Two curators at a major new Egyptian antiquities museum have been arrested on suspicion of stealing ancient artifacts and replacing them with replicas, officials told NBC News. The curators at the National Museum of Egyptian Civilization removed a statue dating back 4,000 years. The employees are also suspected of plotting to steal an Islamic vase dating back to the Mamluk period, museum officials said. A police report is pending, but Khaled El Enany, the museum's general supervisor, told NBC News that the curators may be part of a larger network. El Enany pledged that security of Egyptian antiquities would improve upon the museum's official opening. "When we open, it will be safe," he said. "There will be tourists, and security."