Hundreds of thousands of Iranian citizens have gathered in downtown Tehran to bid farewell to the slain General Qassem Soleimani, who was killed by drone at Baghdad International Airport.

The order to carry out an air strike was issued by US President Donald Trump, while the body of General Soleimani has arrived in Iran, with burial expected to take place today.

Tehran's streets are crowded, and its coffin is passing through the main square of the Iranian capital, holding its sympathizers in its hands.

Many of the participants are holding portraits of Soleiman and the Iranian flag, and some have been reluctant to wear transparencies against the US with inscriptions such as "Down Under the US".

Many Iranians regard Soleiman as a national hero and therefore chant "Death to America". On the other hand, Iran's supreme leader, Ali Hamnei Khamenei, has prayed in front of Commander Qassem Soleimani's coffin.

Meanwhile, local media have reported that over one million citizens have taken to the streets, and, as Retuers reports, is being described as the largest rally since 1989 when it was held during the burial of Islamic Republic founder Ayatollah Khamenei.