The United States has been flying surveillance drones over Gaza in search of hostages taken by Hamas, according to Reuters.

The two US officials, speaking on the condition of anonymity, said the US is flying intelligence gathering drones over Gaza to assist with hostage location efforts. One of the officials said they have been carrying out the drone flights for over a week.

US officials have said 10 Americans who remain unaccounted for may be among the more than 200 people taken as hostages into Gaza, where they are believed to be held in Hamas’ extensive tunnel network.