– Prompted by the unexplained deaths of a middle-age British couple at an Egyptian Red Sea resort this week, their tour company was evacuating 300 foreign guests from their hotel Friday after it received reports that other guests had also fallen ill.

The couple, John and Susan Cooper of Lancashire, England, died within hours of each other at the resort in Hurghada on Tuesday. John Cooper, 69, was found dead in his hotel room midmorning, Egyptian authorities said, while Susan Cooper, 64, who suddenly fell ill, died six hours later after being taken to a hospital.

The evacuation of the other guests at the Steigenberger Aqua Magic Hotel on Friday was the latest blow to Egypt’s tourism industry, which, despite a modest upswing this year, is still struggling to recover from years of political turmoil, plane crashes and Islamist attacks.

Egyptian officials said the couple had died of natural causes. But their travel company, Thomas Cook, said Thursday night that the circumstances of their deaths were still unclear and that it had received reports of a “raised level of illness among guests.”

“As a precautionary measure, we have taken a decision to remove all our customers from this hotel,” the company said in a statement. “We are aware of the speculation in some of today’s media that their deaths may have been caused by carbon monoxide poisoning. Currently, we have no evidence to support this.”

That speculation, carried mostly in the British tabloid media, cited the deaths in 2006 of two children from carbon monoxide poisoning in their hotel room during a holiday in Greece. That tragedy drew sharp criticism for Thomas Cook.

As hundreds of mostly British vacationers prepared to fly out of Egypt on Friday, some took to social media to offer other explanations, such as food poisoning, that deepened the sense of confusion surrounding the couple’s deaths.

In its statement, the Red Sea governorate, which covers the area where the couple died, said that there was no suspicion of “criminal activity.” An initial examination by Egyptian health officials showed that John Cooper had suffered a heart attack, authorities said.

Susan Cooper was transferred to a hospital “in a state of fainting,” authorities said. Doctors tried unsuccessfully to resuscitate her, and Egyptian officials determined that she had died from “a drop in blood circulation and respiratory functions with no criminal suspicions.”