Mohammed Amzarba, the head of Aden's port authority was cited by the official Saba news agency on Thursday as saying that the vessel, named Dia had started to sink after years of being abandoned at the port. Authorities reportedly tried to tow it using a tugboat before it eventually sank, partly due to a lack of specialised equipment.
One unnamed source at the port authority disclosed that the oil slick had spread along the coast for some 20 kilometres.
One member of the environmental rescue committee in Aden, Ahmed Fahim, explained that no one had taken "care of the maintenance of the tanker, so it sank and caused a disaster on the coast." Adding that dead fish had "washed up on shore."
However, according to the Sanaa-based Yemen Press Agency, the Minister of Fisheries in the Houthi-aligned government, Mohammed Al-Zubayri, accused the Saudi-backed international government and the UAE-supported Southern Transitional Council, who control much of the port city of being responsible for the oil spill.
"The ships of the aggressive Saudi-UAE coalition allocate oils and waste near the Yemeni coasts, with the systematic aim of disrupting the ports and affecting the marine environment," Al-Zubayri said, warning that the oil spill would affect fish, seagrass, and coral reefs.
"We have approximately 290 fishermen who are missing due to the systematic targeting of fishermen by Saudi-UAE aggressors," he added.
The sinking of Dia has also reignited pre-existing environmental and humanitarian concerns over the abandoned oil tanker, the 45-year-old FSO Safer vessel which has been anchored near the strategic western Red Sea port of Al-Hudaydah, which has been under blockade by the Saudi-coalition since March 2015.
Both the de facto government in Sanaa and Riyadh have traded accusations as to who is ultimately responsible for the fate of the tanker. Last year, a Houthi official announced that a rescue team had been dispatched to the Safer to carry out maintenance work.
The UN-recognised government-in-exile has blamed the Houthi authorities for any leaks from the tanker because it's moored in territory under their control. However, Sanaa has insisted that it is the coalition which should be held accountable as it controls the waters near the vessel and has also prevented the Houthis from selling the oil which is still on board.