JAKARTA — Two more bodies were found and two large metal objects were located in the sea bed as recovery teams expanded the search area for the AirAsia plane that crashed more than one week ago, an Indonesian official said on Jan 6.

“Strong current has pushed the victims and debris eastward and forced the rescuer to expand the search area by about 100 square miles (260 square km),” Indonesia search and rescue agency chief Bambang Soelistyo told a news conference on the 10th day of the rescue operation that involves several countries.

So far, 39 bodies out of total 162 people on board have been recovered since the plane crashed into the Java Sea on Dec 28 as the operation is hindered by unfriendly sea conditions.

According to Soelistyo, two large objects have been identified by US Fort Worth ship during the operation on Jan 6. However, the strong current impeded the operation of remote-operated underwater vehicles and divers’ attempts to investigate the debris, he added.

However, recovery workers are yet to find the black boxes, crucial to determining the cause of the crash, although they said they have found the tail part of the plane, where flight recorders are usually housed.

Three Chinese experts from the Civil Aviation Administration of China arrived in Soekarno Hatta Airport early on Jan 6, marking the arrival of the first batch of Chinese aid in the search operation for the black boxes of the crashed AirAsia plane.

“We are here to help the search for the black boxes,” Mao Yanfeng, director of disaster investigation agency under the Civil Aviation Administration of China, told Xinhua while waiting for the domestic flight heading toward the command post established at Pangkalan Bun in Central Kalimantan.

“We can’t elaborate on when the black boxes can be found or how long we will stay in Indonesia before we get more information at Pangkalan Bun,” said Mao, adding that they have brought along with them portable underwater detection equipment and communication device.

Mao is positive on the finding of the black boxes. “The side-scan sonar could also locate the black boxes, even after 30 days when the boxes go dead,” he said.

The Chinese aviation expert said that “no pings have been detected from the boxes, the reason could be complicated,” citing the internal failure of the black boxes or the signal was impeded by mud in the seabed.

At the time, five ships with specialized equipment are conducting the search for the black boxes at Northern Java Sea, according to Soelistyo.

A Chinese rescue ship “Nanhaijiu 101” is expected to arrive directly in Pankalan Bun on Jan 9, after leaving Haikou, capital city of China’s Hainan province, on Jan 5, said China’s Ministry of Transport in a statement.