Four people were killed and 11 wounded in an explosion outside an international trade fair in the Syrian capital Damascus on Sunday, an organizer told dpa.

State television, citing its reporters on the scene, said the rocket hit near the entrance of the exhibition complex where the business fair opened this week.

The breaking news alert gave no details on the number of injured or the source of the rocket fire, and there was no immediate mention of the incident on state news agency SANA.

The Mortar News in Damascus Facebook page that tracks violence in the capital reports that the shell hit the entrance of the Damascus International Fair killing four and wounding four others.

A journalist working for state media confirmed the shelling saying it left "several people martyred or wounded."

The journalist who spoke on condition of anonymity because he is now allowed to speak to other media organizations did not elaborate.