Soldiers inspect the scene of a drone attack at military parade in Yemen, in this file photo taken on January 2019.
The attack in Aden was claimed by the Houthi group.
At least 40 people were killed in an attack on a military parade in the Yemeni port city of Aden on Thursday, security and medical sources said.
There was no immediate comment from the Yemeni government.
The attack in Aden was earlier claimed by Houthi group.