Mysterious damage to vital communications cables under the Red Sea has raised concerns about whether the conflict in the Middle East is now beginning to threaten the global internet.

Just as the waters off Yemen hold crucial shipping lanes, they are also a critical location for undersea cables that carry email and other digital traffic between Asia and the West. Around a dozen cables run through the area, and more are planned.

These bundles of glass fibers, about as thick as a garden hose, “are extremely important,” said Tim Stronge, vice president for research at TeleGeography, which analyzes the telecommunications market. “Over 90 percent of all communications traffic between Europe and Asia goes through those” cables.

Late last month, Seacom, a company that specializes in providing communications to African countries, noticed that data had stopped flowing through its line that runs from Mombasa, Kenya, up through the Red Sea to Zafarana in Egypt.

At the same time two cables linking West to East were knocked out, affecting 25 percent of traffic through the area, according to an estimate by HGC Global Communications, a Hong Kong-based telecommunications company.

In an interview from his office in Johannesburg, Prenesh Padayachee, Seacom’s chief digital and operations officer, said the damage to his company’s cable occurred on the bottom of the Red Sea, in Yemeni waters about 650 feet deep. The two other damaged cables are nearby.

What disabled the cables is still not clear. Suspicion has centered on Yemen’s Houthi rebels, but the Houthis, who have attacked numerous ships in the area in what they say is solidarity with Palestinians in Gaza during the war between Israel and Hamas, have denied responsibility.

Mr. Padayachee said the cause of the damage would remain unknown until a repair vessel managed to pull the wire up and examine it. Candidates include an anchor dragged by a ship, a disturbance on the sea bottom or sabotage. “We will only be able to tell once we lift the cable,” he said.

Arranging repairs is proving difficult. Seacom is working with a company called E-marine, which has boats in nearby Oman, to address the problem, but Mr. Padayeechee acknowledged that the job requires assessing the political situation and obtaining permits from Yemen.

He said he was hopeful that the work might get underway sometime next month.

While Seacom has been able to arrange for most of its internet traffic to be rerouted through other cables, Mr. Padayachee said he chafed at the regional instability hampering the repair effort. “We would prefer to have definitive timelines that aren’t dictated by geopolitical situations,” he said.

Having so many cables running through such a volatile area is also a concern. Individual lines are relatively easy to damage. While cables are buried and armored near shore, further out at sea they lie on the bottom with little protection.

Mr. Stronge estimated that there were roughly 500 undersea cables globally and an average of 100 breaks a year. Most of the time, some sort of marine accident like an anchor dragging turns out to be the cause, he said.

Mr. Stronge said that what compensated for the fragility of individual cables was the redundancy that operators built into the system. He said that even if all the cables in the Red Sea were severed, internet traffic, like tankers, could be rerouted around the Cape of Good Hope at the tip of Africa or eastward through Singapore, Japan and across the United States to Europe. “It is slower, but it can be done,” he said.