With the government shutting down the internet and throttling phone services, Iranians are leaning heavily on Elon Musk’s Starlink service to share videos of growing protests and the regime’s escalating crackdown with the world.

But Iran has intensified efforts to jam the service, which is banned in the country, and users are being hunted.

Over the weekend, authorities began searching for and confiscating Starlink dishes in western Tehran, said Amir Rashidi , director of digital rights and security at Miaan Group, a U.S. nonprofit opposed to internet censorship.

“It’s electronic warfare,” Rashidi said. He said disruptions are worst in parts of Tehran where protests are taking place and in the evening, when the demonstrators gather.

The battle over information—while secondary to the confrontations taking place nightly in dozens of cities across Iran—has potentially serious consequences. President Trump has threatened to intervene in response to a crackdown by the regime.

Video from the streets is one of the few ways of getting information out about the scale of the protests and the actions of Iranian authorities.

More than 500 people have been killed in the unrest, according to the group Human Rights Activists in Iran. Another rights group, Hengaw Organization for Human Rights, circulated video footage Sunday showing a large number of bodies at a morgue in south Tehran.

Trump is scheduled to be briefed Tuesday on his options . One under discussion is to send in more Starlink terminals. Trump said he would ask Musk about the possibility.

“We may get the internet going if that’s possible,” Trump told the reporters.

Iran shut down most internet connections for the country’s 90 million inhabitants late last week, after protests over a crippling economic crisis exploded into large-scale unrest with demonstrators chanting for an end to the regime. The government has also made it difficult to connect calls or send text messages.

The only exceptions are the government itself, its media services and regime loyalists who are registered on a “whitelist” of internet addresses, said diplomats and others communicating with some of those with uninterrupted access.

In one message Sunday, the government told people to rely on news from the Mehr agency, which is affiliated with the security services. Another text called on Iranians to join a pro-government demonstration Monday at the University of Tehran, a stronghold of recent protests.

“The Iran government invites the people to join a demonstration in support of the regime and against US & Israel,” it said.

The rest of the country relies on Starlink to send out footage of the demonstrations.

“It is the only way,” said Mahmood Amiry-Moghaddam , co-founder of Iran Human Rights, both based in Norway. He said he received footage of protests in Mashhad, Iran’s second largest city by population.

A user in Tehran, who spoke to The Wall Street Journal through a Starlink connection early Sunday, said he had uploaded protest videos taken by relatives. He then sent them to third parties abroad who posted them on social media.

People who have Starlinks don’t let it be known and only upload videos to people they trust, he said over his crackling and distorted Starlink connection.

The government’s efforts to interrupt the service have slowed down Starlink access but haven’t stopped it, said Mehdi Yahyanejad , co-founder and board director at NetFreedom Pioneers. The U.S. group helps people in authoritarian nations get access to the internet.

When Iranian users get good connections, often in the morning or midday, they transmit as many videos as they can, Yahyanejad said.

Starlink terminals are illegal in Iran and had to be smuggled in, often on small boats from Dubai or across the border from Iraqi Kurdistan.

They started to show up in big numbers at the end of the last big wave of protests in 2022, when Musk said his company would seek an exemption to sanctions for his terminals.

Yahyanejad said his organization, NetFreedom, sent thousands of Starlink kits to nonprofits in the country. Others were brought in via commercial intermediaries.

Iran has pushed the U.S. through the International Telecommunication Union, a United Nations agency, to ban Starlink service within its territory. The U.S. and Starlink have resisted enforcing the ban beyond cutting off terminals identified by Iran.

The internet shutdown is deepening the economic crisis that triggered the protests. Businesses in Iran—already struggling with sanctions, inflation and now widespread strikes—have been hit by the loss of online services and the frequent interruption of domestic calls, Iranians abroad who have spoken to their contacts in Iran said.

“Because there is no email, their business is at standstill,” Rashidi said.

Write to Benoit Faucon at benoit.faucon@wsj.com