BEIJING, March 11 -- A South China Sea rescue vessel with hull number 115 has joined the search for the still missing Malaysia Airlines passenger plane, the China Maritime Search and Rescue Center announced Tuesday.

The vessel reached the search area at 8 p.m. Monday. As of 9 a.m. Tuesday, Chinese search ships, including the Mianyang frigate, had scoured 7,717 square kilometers of waters, but no suspected debris or objects were found underwater or at the water's surface, the center said.

A second Chinese naval vessel also cruised into position on Tuesday morning and joined the international hunt for missing Malaysia Airlines Flight MH370.

The center said another two Chinese search and rescue vessels are expected to reach the search area by Tuesday afternoon.