Updated

The last five Chinese fishing boats at the center of a dangerous impasse between China and the Philippines have left a disputed shoal in the South China Sea, officials said Saturday.

Their departure diffused the standoff but also embarrassed the Philippines, which had insisted on confiscating the fishermen's alleged illegal catch of endangered giant clams, corals and live sharks.

Foreign Affairs Secretary Albert del Rosario confirmed that the Chinese fishing boats departed late Friday from Scarborough Shoal, off the northwestern Philippines.

In a later statement, he said that China sent back one of its surveillance ships to the shoal, bringing to two the number of vessels facing off a Philippine coast guard frigate.

He also accused China of flying an aircraft near the Philippine frigate, and said that a "white Chinese ship harassed a Philippine-registered vessel with nine French nationals, which has been conducting archaeological surveys."

"It appears there is an element that is lacking in our negotiations. I seek a deeper element of trust from our Chinese friends," del Rosario said.

He said that his meeting with Chinese Ambassador Ma Keqing on Friday night "resulted in a stalemate," with both sides insisting that the other nation's ship be the first to leave the area.

He said the Philippines would continue to monitor the situation at the shoal.

Both sides claim the uninhabited, horseshoe-shaped shoal, which lies 230 kilometers (124 nautical miles) from Zambales province, the nearest Philippine coast.

The impasse began Tuesday when Chinese ships prevented the Philippine navy from detaining Chinese fishermen allegedly caught poaching.

There were initially eight Chinese fishing boats seen in the area, but the number increased to 12 at one point, said Lt. Gen. Anthony Alcantara, the regional military commander.

The other boats pulled out earlier.

The impasse has reignited concerns about potential conflict in the South China Sea, one of the world's busiest seas lanes and home to a myriad of competing territorial claims, most notably the Spratly Islands, which are south of the shoal.

The disputes have settled into an uneasy standoff since the last major clash, which involved China and Vietnam and killed more than 70 Vietnamese sailors in 1988.