Russian military personnel have delivered 14 MiG 29 and Su-24 fighter jets to the Libyan National Army's Jufra air base, the U.S. military says, despite denials from the LNA and a Russian member of parliament.
Iran's airlines have been plagued by crashes, which Iranian rulers blame on U.S. sanctions that block the airlines from replacing their ageing fleets or purchasing spare parts from the West.
Iran said on Tuesday it had arrested an undisclosed number of suspects accused of a role in shooting down a Ukrainian airliner, as anti-government demonstrations triggered by the disaster entered a fourth day.
Britain is keeping the security of its embassy in Tehran under review after Iran briefly arrested London's envoy to the country, foreign minister Dominic Raab said on Monday.
Images and reports of the protests were carried by state-affiliated news agencies, alongside videos on social media.
Iran had denied for days after Wednesday's crash that it brought down the plane, although a top Revolutionary Guards commander said on Saturday that he had informed the authorities about the unintentional missile strike the same day it happened.
All 176 people on board, including 63 Canadians, were killed on Wednesday shortly after it took off from Tehran on a flight to Kiev. Iran denies its forces brought down the plane.
The Ukrainian International Airlines Boeing 737-800, flying to Kiev and carrying mostly Iranians and Iranian-Canadians, crashed shortly after taking off on Wednesday from Tehran's Imam Khomeini airport.