KYIV, Jan 14 - Iran said on Tuesday it had arrested people accused of a role in shooting down a Ukrainian airliner and had also detained 30 people involved in protests that have swept the nation for four days since the military belatedly admitted its error, Reuters reported.

Wednesday’s downing of Ukraine International Airlines flight 752, which killed all 176 people aboard, has created a new crisis for the Islamic Republic’s clerical rulers.

President Hassan Rouhani promised a thorough investigation into the “unforgivable error” in an address on Tuesday. It was the latest in a series of apologies by the leadership that has done little to quell public anger.

The latest developments come as new security camera footage shows two Iranian missiles, fired 30 seconds apart, hit the airliner after takeoff from an airport in Tehran, according to the New York Times.

The missiles were launched from an Iranian military facility eight miles away from the plane, the newspaper said. Neither missile took down the plane immediately and the video shows the plane on fire and circling back toward Tehran airport, it said.

A person who posted a video online last week of a missile striking the plane has been taken into custody by the elite Revolutionary Guards, the semi-official Fars news agency reported.

Iranian judiciary spokesman Gholamhossein Esmaili said some of those accused of having a role in the plane disaster had been arrested, although he did not say how many or identify them.

London will host a meeting on Thursday of Canada, Ukraine, Britain and other nations who had citizens on the plane. Ukraine said they would consider legal action against Tehran.

Rouhani said the government would be accountable to Iranians and those nations who lost citizens. Most of those on board the flight were Iranians or dual nationals and 57 were Canadian.

A team of Canadian experts joining the investigation visited the crash site on Tuesday, an Iranian news agency reported. It followed a meeting in Tehran between experts from Canada, Ukraine and Iran.

Canadian Prime Minister Justin Trudeau asked for Kiev’s help in talking to Iran about identifying the bodies of the Canadian citizens who were killed, the Ukrainian president’s office said. (rt/ez)