On Wednesday afternoon, an explosion near Sanchi’s bow forced response vessels to temporarily retreat from their positions, a further setback to efforts to extinguish the fire and locate 31 missing crewmembers. According to the Chinese Ministry of Transport, the rescue crews had been applying firefighting foam at the time of the explosion. The extent of any damage to the Sanchi from the blast is not yet known.

Poor weather has also complicated the response effort. Forecasts for Wednesday showed winds of 25-30 knots in the East China Sea search area, with waves of 10-15 feet.

In a statement carried by an Iranian state news outlet, the vessel’s operator said that rescue teams will enter the tanker as soon as the fire is brought under control. Captain Mohsen Bahrami, spokesman for the National Iranian Tanker Company, said two fireboats are fighting the fire and that a number of other fireboats will join the operation soon. “Saving the missing tanker crew is NITC’s first priority for the time being and all the available equipment inside or outside of Iran have been mobilized to find them,” he said.

The two vessels collided about 160 nm off Shanghai on Saturday night while Sanchi was under way for Daesan, South Korea. The CF Crystal escaped without critical damage, and her AIS signal showed that as of Wednesday she was berthed west of Zhoushan, China. Earlier in the week, Chinese officials said that she would be headed into port for an investigation into the cause of the incident.

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