DUBAI, United Arab Emirates (AP) — Iranians could call abroad on mobile phones Tuesday for the first time since communications were halted during a crackdown on nationwide protests in which activists said at least 646 people have been killed.

Several people in Tehran were able to call The Associated Press and speak to a journalist there. The AP bureau in Dubai, United Arab Emirates, was unable to call those numbers back. The witnesses said SMS text messaging still was down and that internet users in Iran could connect to government-approved websites locally but nothing abroad.

The witnesses gave a brief glimpse into life on the streets of the Iranian capital over the four and a half days of being cut off from the world. They described seeing a heavy security presence in central Tehran.

Anti-riot police officers, wearing helmets and body armor, carried batons, shields, shotguns and tear gas launchers. They stood watch at major intersections. Nearby, the witnesses saw members of the Revolutionary Guard's all-volunteer Basij force, who similarly carried firearms and batons. Security officials in plainclothes were visible in public spaces as well.

Several banks and government offices were burned during the unrest, they said. ATMs had been smashed and banks struggled to complete transactions without the internet, the witnesses added.

However, shops were open, though there was little foot traffic in the capital. Tehran's Grand Bazaar, where the demonstrations began Dec. 28, was to open Tuesday. However, a witness described speaking to multiple shopkeepers who said the security forces ordered them to reopen no matter what. Iranian state media had not acknowledged that order.

The witnesses spoke on condition of anonymity for fear of reprisal.

U.S. President Donald Trump has said Iran wants to negotiate with Washington after his threat to strike the Islamic Republic over its crackdown.

Iranian Foreign Minister Abbas Araghchi, speaking to the Qatar-funded satellite news network Al Jazeera in an interview aired Monday night, said he continued to communicate with U.S. envoy Steve Witkoff.

The communication “continued before and after the protests and are still ongoing," Araghchi said. However, “Washington’s proposed ideas and threats against our country are incompatible.”

White House press secretary Karoline Leavitt said Iran’s public rhetoric diverges from the private messaging the administration has received from Tehran in recent days.

“I think the president has an interest in exploring those messages,” Leavitt said. “However, with that said, the president has shown he’s unafraid to use military options if and when he deems necessary, and nobody knows that better than Iran.”

“Death to Israel!”  Others cried out, “Death to the enemies of God!” Iran’s attorney general has warned that anyone taking part in protests will be considered an “enemy of God,” a death-penalty charge.

Trump announced Monday that countries doing business with Iran will face 25% tariffs from the United States. Trump announced the tariffs in a social media posting, saying they would be “effective immediately.”

It was action against Iran for the protest crackdown from Trump, who believes exacting tariffs can be a useful tool in prodding friends and foes on the global stage to bend to his will.

Brazil, China, Russia, Turkey and the United Arab Emirates are among economies that do business with Tehran.

Trump said Sunday that his administration was in talks to set up a meeting with Tehran, but cautioned that he may have to act first as reports of the death toll in Iran mount and the government continues to arrest protesters.

“I think they’re tired of being beat up by the United States,” Trump said. “Iran wants to negotiate.”

Iran, through the country’s parliamentary speaker, warned Sunday that the U.S. military and Israel would be “legitimate targets” if Washington uses force to protect demonstrators.

More than 10,700 people also have been detained over the two weeks of protests, said the U.S.-based Human Rights Activists News Agency, which has been accurate in previous unrest in recent years and gave the latest death toll early Tuesday. It relies on supporters in Iran crosschecking information. It said 512 of the dead were protesters and 134 were security force members.

With the internet down in Iran, gauging the demonstrations from abroad has grown more difficult. The Associated Press has been unable to independently assess the toll. Iran’s government hasn’t offered overall casualty figures.