Yemen is in turmoil: The Arab state is now at the heart of a regional conflict pitting a long-standing rebellion against an enfeebled Saudi-backed government.

The factions are now battling over the southern coastal city of Aden, which the country's president was forced to abandon last week. And the country's Internet connectivity is one of the victims of the fighting. Aden is the access point for one of only two submarine cables that connects Yemen to the global Internet -- and researchers noted two major disruptions where that cable, which connects Yemen to Djibouti, appears to have gone dark in the last two days.

But Yemen isn't alone. When conflict strikes, Internet access is often an early casualty -- cutting off communications for civilians when they need it the most.

"When there's some sort of conflict, communications ends up being damaged or in some cases intentionally disconnected," said Doug Madory, who watches global online routing data from his perch in New Hampshire as the director of Internet analysis for  Dyn. The effects can be particularly harmful in the developing world, where infrastructure is less robust than in other nations.

Such is the case with Yemen, whose Internet infrastructure is controlled by one state-run provider and relies on a handful of access points to just two submarine fiber cables. Internet stability in Yemen started to get rocky on Monday, Madory said. But the apparent outages of the Djibouti cable, starting Wednesday as fighting intensified in Aden, caused more significant disruptions. "It's safe to say that national Internet connectivity during that time was degraded," he said.

The cause of the outages remain unclear, although their limited time frame -- the first one lasted roughly an hour and half -- suggests they were likely related to power blackouts or fixable equipment failures rather than an attack aimed at cutting off Internet access, Madory said.

But in other recent conflicts, Internet infrastructure seems to have been purposely targeted. The Egyptian government reportedly shut down Internet access in the midst of the Arab Spring, drawing outcry from the U.S. government and others. And the entire country of Sudan suffered an extended outage during rioting in the capital city of Khartoum in 2013.

Syria, which has been embroiled in a years-long civil war, has also suffered nation-wide and localized Internet outages -- although the sources of those outages have been the subject of debate.

It's often difficult to determine the culprit when communications infrastructure is attacked. And in some cases, anti-government groups have also forced outages. In one 2013 incident, the BBC reported that demonstrators in Libya stormed a state-owned Internet provider and forced it to switch off service. In Yemen, local reports suggested Internet cables were targeted by tribal groups during disputes with the government in years past.

The Internet has become a powerful tool for journalists documenting conflicts and civilians eager to get information about the facts on the ground. But when it goes dark, either due to deliberate attacks or the failure of insufficient infrastructure, those who depend on it are often left without recourse -- sometimes for hours, sometimes for days.

"All the facts in the world available in real time won’t make a whit of difference if people don’t have access," U.S. Secretary of State John Kerry noted during remarks to an online freedom conference last year. "And for millions of people today, that is the reality of the challenge that they face."