Dozens of Iranian students opposed to the nuclear agreement with world powers gathered in front of parliament Tuesday, urging lawmakers to reject the deal, several local media reported.
Both the Iranian parliament, as well as the US Congress, are currently reviewing the deal before voting on it and potentially implementing it.
Congress is expected to pass a resolution next month opposing the deal. President Barack Obama will veto that measure, but Congress could override such a veto – and kill the deal – with a two-thirds majority in both the Senate and House of Representatives.
Iranian lawmakers are believed to be waiting to see what Congress decides.
Students chanted slogans against the "US intrusion in Iran" through the agreement, and also against the "weak Majlis (parliament)," which they said has been "a partner in crime with the government" on the issue.
Some held banners calling the deal an "American Trojan horse to infiltrate Iran."
The conservatives questioned the achievements of the deal and said "sanctions remain but our dignity is violated," despite the fact that the deal is to provide hundreds of millions of dollars in sanctions relief.
The students also protested the arrest of some hardliners Sunday in front of the British embassy in Tehran, which was reopened by Foreign Secretary Philip Hammond the same day.
Around 40 protesters had chanted anti-British slogans, and some were arrested but released later in the day.
Iran did not bother to cover up the graffiti reading "death to England" still scrawled on several places in the embassy, including right above a portrait of Queen Elizabeth.
AFP contributed to this report.