ADEN — Violent clashes broke out between Hirak (the Southern Movement) and Islah party supporters in the city of Aden on Tuesday night.

Each side was participating in separate marches celebrating the May 22 national Unity Day. Hirak commemorates the anniversary of what they see as a failed declaration of secession from Sana'a in 1994, whereas Islah celebrates National Unity Day announced on May 22, 1990.

Hirak organized two marches that set off from Aden’s Al-Mualla district and ended in Crater district, where Islah was marching. When the rival parties met they started chanting slogans at each other. Clashes followed with supporters shooting fireworks, hurling stones and eventually shooting firearms at each other.

Although no official human casualty has been reported, eyewitnesses told the Yemen Times that several people had been injured during what they called "fierce clashes.”

Hirak members and activists claimed that they had successfully thwarted the anniversary celebrations of the national holiday. Islah leaders, for their part, condemned what they called a “botched bid” to derail the celebration. They accused “Hirak thugs” of supporting violent actions.

Aden has witnessed numerous violent clashes between Hirak and Islah affiliates, which have resulted in scores of injuries. In February 2012, armed members of the Southern Movement stormed an Islah camp in Al-Mualla.

The Southern Movement started in 2007 with popular demonstrations in southern Yemeni governorates calling for equal citizenship and an end to corruption. The call then developed into demands of separation from the north.

Political leaders from the two halves announced unification in May 1990.