BEIJING, Jan. 7 (Xinhua) -- China is ready to send additional forces to help search the ill-fated AirAsia Flight QZ8501 according to the needs of Indonesia, Foreign Ministry spokesman Hong Lei said Wednesday.

"China has attached great importance to participating in the search operation and maintained close contact with Indonesia," Hong told a routine press briefing.

Three experts from the Civil Aviation Administration of China arrived in Soekarno Hatta Airport early Tuesday morning, marking the arrival of the first batch of Chinese aid in the search operation.

They brought portable underwater detection equipment and communication devices.

Equipped with underwater detection devices, the rescue ship "South Sea Rescue 101" had left the city of Haikou and is expected to arrive at the search site on Jan. 9.

Meanwhile, another vessel, "South Sea Rescue 115," is on standby, the Ministry of Transport said Monday.

In response to a request from Indonesia, a Chinese rescue vessel, Yongxingdao, of the People's Liberation Army Navy, is also expected to arrive at the search site on Jan. 9, according to the naval authorities.

The AirAsia flight is believed to have crashed into the Java Sea on Dec.28, with 162 people onboard.

So far, 40 bodies have been discovered by a multinational search team.

Searchers found Wednesday the tail of the plane on the sea bed about 30 km from its last known location, but the black box is yet to be found.