HANOI: Vietnamese rescuers have found some pieces belonging to a search plane that went missing with nine people aboard while attempting to locate a pilot from a crashed fighter jet, the military said Friday.

The pieces including wreckage bearing the logo of the search plane, a tire, a seat and personal belongings of crew members were discovered 20 nautical miles (23 miles or 37 kilometres) southeast of Bach Long Vi island and 3 nautical miles east of the demarcation line between Vietnam and China in the Gulf of Tonkin, the Ministry of Defense said in a statement.

The plane lost contact with command center early Thursday afternoon, some 44 nautical miles (81 kilometres) southwest of Bach Long Vi island, off the coast of northern port city of Hai Phong.

Meanwhile, online newspaper VnExpress quoted Maj. Gen. Nguyen Quang Dam, commander of the maritime police, as saying bad weather may be blamed for the aircraft's crash. Dam said the crew asked to descend to lower altitude when experiencing unexpected bad weather.

Thanh Nien quoted weather forecaster Nguyen Dinh Thuat as saying there was rain and strong wind at the time the aircraft lost contact.

The ministry statement said China has sent two vessels to join the search and rescue operations.

The nine people on board are among 1,500 personnel sent to search for the pilot, whose Russian-made Sukhoi Su-30 MK2 jet fighter crashed Tuesday on a training flight. One other pilot from the jet was rescued by a fishing boat Wednesday.

Ho Chi Minh City Law newspaper reported that plane searches were suspended late Friday morning because of bad weather.

Officials were not available for comment on Friday.

The incidents were the latest in a string of accidents to hit the military. At least two crashes of military helicopters in the past two years have killed 24 people.