TEL AVIV, Israel — Juliette Touma is the director of communications for the United Nations agency that delivers aid to Gaza. She was there earlier this week, but she couldn't do her job.

"I mean I couldn't even hold a phone call to record an interview, like I'm doing with you now," Touma told NPR shortly after she returned.

Gaza is approaching a week without internet and cellphone service. The lack of communications is making it difficult for the U.N. to distribute the small amount of food and supplies it can get into the territory, which has been under heavy Israeli bombardment since shortly after Hamas militants attacked Israel in October.

"For aid operations and to coordinate the delivery of assistance it's extremely difficult not to have a phone line," she said.

Gaza has had blackouts before, most notably when Israel sent ground troops into the territory in late October. But this one is different, according to Alp Toker, director of Netblocks, a company that tracks disruption to internet services in conflict zones.

"This one is now the longest single such blackout," he said.

But Toker said he doubts the blackout is due to something like an Israeli cyberattack.

Its length is unusual, and it doesn't appear to coincide with any specific Israeli operation, he said. "It's too easy an answer to just say look, Israel is just flicking on and off the service at will."

In a statement posted shortly after the latest blackout began, Paltel, Gaza's main internet provider, blamed "ongoing aggression" for the problem.

Samer Fares, director of Palestinian mobile provider Ooredoo, told NPR that an underground fiber-optic line connecting internet and cellphone towers in Gaza to Israel and the West Bank was severed by Israeli military activity in the vicinity of Khan Younis in southern Gaza.

"Paltel has been trying to fix the cut in the line, but they haven't been able to because of intense military operations in the area," he said.

In fact, two Paltel workers were killed last week as they drove out to make repairs. Fares said they were struck by Israeli tank fire.

Fares said that the deaths are slowing repair efforts. "Work in Gaza is very dangerous to everyone," he said. "Although we coordinate for maintenance operations, the bombardment is very intense."

In a statement to NPR, the Israeli military said it's launched an independent investigation into the incident.

Ryan Sturgill is an entrepreneur based in Amman, Jordan, who has been trying to help people get a signal using Israeli and Egyptian cellular networks. He believes that the ongoing blackout is undoubtedly imperiling the lives of people in Gaza.

Without phones, civilians can't call ambulances for help if they are wounded, or warn each other of dangerous areas to avoid. The Israeli military is continuing to announce "safe corridors" on social media, but people in Gaza can't see them if they don't have service.

"Access to lifesaving information is just fundamentally reliant on communications," he said.

The U.N. has echoed these concerns. "The blackout of telecommunications prevents people in Gaza from accessing lifesaving information or calling for first responders, and impedes other forms of humanitarian response," it said on Wednesday.

The laws of war date from the last century, and were written well before cellphones. But in the modern era, Sturgill believes connectivity is essential to survival.

"I mean in almost every conflict since the rise of the internet, there has always been some connectivity," he said. "Even a landline."

NPR's Becky Sullivan and Eve Guterman contributed reporting from Tel Aviv and Abu Bakr Bashir from London.