Chinese vessels have covered 646,000 sq km in the Indian Ocean in search of the missing Malaysian flight -- MH370, the China Maritime Search and Rescue Center said.
Search efforts were about 18,000 sq km more than the previous day, Xinhua qutoed the centre as saying Tuesday. The centre has also mobilised 65 merchant ships for assistance, which have covered 176,000 sq km.
No objects related to MH370 have been found, it said.
The international hunt for the plane has been ongoing since the Boeing 777-200 aircraft carrying 227 passengers, including 154 Chinese, and 12 crew members disappeared March 8 while flying from Kuala Lumpur to Beijing.