The salvaging operations on the stranded minesweeper USS Guardian off the Tubbataha Reef in the Philippines has started on Wednesday, with the crane ship Smit Borneo finally allowed to sink its anchor into the Sulu Sea.

The Smit Borneo will drop a total of four anchors 10 meters away from the protected area. The two at the bow will be lowered 800 meters down into the sea, while the two at the stern will drop at 300 meters.

But the actual salvaging operation on the grounded US vessel will start on either Sunday or Monday. The operations may take two months to complete, or until April.

"With good weather, maybe the salvaging can start by Sunday or Monday," Rear Admiral Rodolfo Isorena, Philippine Coast Guard (PCG) commandant, said.

However, in an official notice published on its Web site, the U.S. Department of Defense (DoD) noted the salvage operations on the 23-year-old $227-million vessel is expected to be completed only by December 2013.

Enrico Efren Evangelista, Philippine Coast Guard Palawan District commander, noting the earlier apprehensions of concerned sectors regarding the lowering of an anchor into the protected area, said the operation was approved to go.

"The operation was allowed after concerned government agencies, including the Tubbataha Protected Areas Management Board (TPAMB), approved the salvage plan presented by Smit Borneo," Mr Evangelista, also chair of Task Force Tubbataha, said.

He likewise pointed out that the TPAMB issued a manifest stating its approval to the plan to lower the anchors far from the damaged reef.

"Ten meters (from the edge of the reef) is already a very safe distance," he said.

Once the minesweeper has finally been extracted from the protected Tubbataha Reef area, divers will again be sent in to assess the overall damage made to the corals.

According to the state-run Philippines News Agency, the grounding of the USS Guardian has damaged an estimated 4,000 square meters or about 43,000 square feet of the reef.

Both the U.S. Navy and the Philippines Coast Guard are investigating the officials responsible for the unfortunate incident.

Leila de Lima, Philippine justice secretary, had said on Tuesday that she is just waiting for the results of the ongoing probe before any legal action is decided and taken against the officials of the U.S. vessel.

Read more:

Tubbataha Reef at Greater Risk with Crane Ships Sent to Pull Out US Ship

Tubbataha Reef Damage to be Compensated -- US Embassy in Manila