An Iranian oil tanker, which had caught fire after it collided with a Chinese freight ship carrying grain on January 7, sank on Sunday, several media reports said quoting the Chinese state television.
The Sanchi was set ablaze in the East China Sea after a collision last Saturday with the CF Crystal, a ship hauling US grain to China.
The administration said it would expand the scope of its monitoring and "quickly ascertain the spread and drift of overflowing oil" from the wrecked ship. Previously, rescuers had found the bodies of two sailors from the Iranian tanker SANCHI. One body was recovered from the sea earlier this week, leaving 29 crew members still unaccounted for.
Dramatic photos of the scene showed tall flames raging on board the ship, which was carrying nearly a million barrels of crude oil.
The cause of the collision remains unclear.
The crew was all Iranian expect for two Bangladeshis. All 32 crew members aboard the vessel presumably died within the first hour of the incident, spokesman for Iran's rescue team Mohammed Rastad said.
The Chinese freighter CF Crystal that collided with the Panamanian-registered tanker had 21 crew members, who all were reported safe.