Clashes renewed between the police and armed gangs after Friday prayers in Al-Saadah quarter in Yemen's business capital of Aden, independent sources said.

Today's confrontations were triggered by the death of a prisoner who was arrested when people took to streets on Thursday to protest mass arrests after Saturday's deadly terrorist attack on the political security office in the province.

The cause of the death remained unclear.

Ahmed Al-Darwish was among about 9 people arrested in connection with the attack that the authorities said bore the hallmarks of Al-Qaeda.

Some reports noted that more than 20 arrests took place when police raided homes and carried out mass arrests in Al-Saadah and Alnasr quarters in Khour Maksar district known as hotbeds of armed outlaws and suspected terrorists.

Most of the arrested were suspected Al-Qaeda operatives, according to security sources. The raids triggered clashes between armed gangs and the police.

On Saturday, gunmen broke into the office in Al-Towahi city shooting bullets and detonating bombs at guards and civilians. Seven soldiers, three women and a child were killed and 15 others were injured.

A day later, the authorities said the mastermind of the attack had been arrested. He was identified as Ghawdal Muhammad Saleh Naji, who the authorities said was a terrorist.

Meanwhile, the Interior Ministry ordered the security forces to stay on heightened alert to face possible attacks and watch the southern coastline to prevent terrorists from infiltrating into the country.