Foreign affairs spokesman Raul Hernandez said Saturday that Manila wants Beijing to explain why the Chinese frigate became stuck on Half Moon Shoal, about 110 kilometers (70 miles) from the western province of Palawan.

"We need to find out what really happened with the Chinese frigate in our territory," Hernandez said.

He said the Philippine Embassy in Beijing has been instructed to inform China's Foreign Ministry that Manila is "willing to help the frigate get out of there."

Defense department spokesman Peter Paul Galvez said a military aircraft spotted six other Chinese ships near the stricken vessel on Saturday.

"We are seeking a clarification from the Chinese what these ships are doing in the area, though it can be assumed that these are out for rescue," he said.

China's Foreign Ministry said in a brief statement on its website that no one was injured when the accident occurred Wednesday as the ship was patrolling near the shoal.

Brig. Gen. Elmer Amon, deputy chief of the Philippine military's Western Command, said the frigate appeared to be in distress and a coast guard vessel had moved within sight of the ship to provide any assistance.

He said the outcropping, called Hasa Hasa Shoal in the Philippines, is well within Manila's territory.

Earlier this year Manila and Beijing became locked in a tense monthslong naval standoff at Scarborough Shoal, another area claimed by both nations in the South China Sea, after the Philippines accused Chinese fishermen of poaching in its waters.

Scarborough is about 710 kilometers north of Half Moon and 235 kilometers off the province of Zambales northwest of Manila.