Iran has appeared to reverse course after its earlier decision to send abroad the black box flight recorders from the Ukrainian jetliner shot down earlier this month, saying Tehran would first review the audiotapes.

Hassan Rezaeifar, who is leading the investigation into the tragedy, was cited by the state-run IRNA news agency on Sunday as saying: "The flight recorders from the Ukrainian Boeing are in Iranian hands and we have no plans to send them out.''

Read more: Opinion: Iran is not about to collapse

"We are trying to read the black boxes here in Iran. Otherwise, our options are Ukraine and France, but no decision has been taken so far to send them to another country," he added.

A day earlier, another Iranian news agency, semi-official Tasnim, cited Rezaeifar as saying that it was not possible to interpret the recordings in Iran, and that the black boxes would be sent to Kyiv, where French, American and Canadian experts would help analyze them.

All passengers killed

The air defenses of Iran's Revolutionary Guard shot the plane down shortly after it took off from Tehran on January 8, killing all 176 people on board.

Watch video 02:02 Share Khamenei leads Friday prayers Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/3WMWP Khamenei delivers rare Friday sermon amid unrest in Iran

Hours earlier, the Guard had launched ballistic missiles at US troops in Iraq in response to the American airstrike that killed Iran's top general in Baghdad.

Officials say lower-level officers mistook the plane for a US cruise missile.

Read more: Germany's Heiko Maas criticizes US for Iran strategy

Canadian Prime Minister Justin Trudeau has been calling for a full investigation into the accident, insisting Iran should send the black boxes to France for further analysis.

The victims included 57 Canadians, 11 Ukrainians, 17 Swedish citizens, four Afghans and four people from the UK.

The majority of those who died in the crash were from Iran. The other four nations who had victims have demanded Tehran accept full responsibility, as well as pay compensation to the relatives of those that died in the tragedy.

The plane was a Boeing 737-800 that was designed and constructed in the United States. The engine was designed by CFM International, a joint operation between French group Safran and US group GE Aviation.

Watch video 00:29 Trudeau: 'Iran must take full responsibility'

mm/rc (AP, Reuters)

Each evening at 1830 UTC, DW's editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here.