Iranian President Hassan Rouhani appealed on Wednesday for “unity” and flagged the need for radical changes to the way Iran is run, after a wave of angry protests over the accidental downing of a Ukrainian airliner.

The Kiev-bound Boeing 737 was shot down in a catastrophic error shortly after takeoff from Tehran, killing all 176 people aboard.

One week on from the disaster, Rouhani called for “national unity” in remarks broadcast live on state television.

“If there was a delay” by the armed forces to release information about what happened, “let them apologise”, he said.

The blunder and its handling by authorities sparked four consecutive nights of protests in Tehran calling for those responsible to resign or be prosecuted, leading to at least 30 arrests.

Iranian Foreign Minister Mohammad Javad Zarif said people were demonstrating because they were deceived for days.

“In Iran … people can state their views. Sometimes they state their views in excessive ways, sometimes the reaction is excessive,” he said in New Delhi.

“But the fact of the matter is, [over the] last few nights we’ve had people in the streets of Tehran, demonstrating against the fact that they were lied to for a couple of days.”

Amnesty International said on Wednesday it had evidence security personnel used “unlawful force” by targeting protesters with rubber bullets, tear gas, pepper spray, and airgun pellets.

The London-based rights group said that “in many cases, the actions by the security forces violated the absolute prohibition of torture and other ill-treatment under international law”.

A student association’s call to protest in Tehran on Wednesday afternoon was cancelled ahead of any gathering taking place.

State-run Islamic Republic News Agency said Iran’s supreme leader Ayatollah Ali Khamenei would lead Friday prayers in Tehran this week. It would be the first time he has done so in nearly eight years.

The latest protests have been much smaller than nationwide demonstrations against fuel price hikes in November that Amnesty International said left more than 300 dead in a crackdown by security forces.

Rouhani also on Wednesday said Iranians wanted “diversity” as he urged electoral authorities to refrain from disqualifying would-be candidates from a February 21 parliamentary election.