A working group from Myanmar has arrived in a border area for a joint investigation with China into a bombing by a Myanmar warplane that killed and injured Chinese.

Reports also said China is increasing patrols in the area to avoid another tragedy.

Chinese Foreign Ministry spokesman Hong Lei confirmed the joint investigation efforts on Monday.

Hong also urged relevant parties to the ongoing conflict in northern Myanmar to "seriously address China's concerns, exercise restraint in real and concrete terms, end the situation quickly and restore order to the border area".

On Friday, a warplane bombed a sugar cane field in the southwestern Chinese border city of Lincang in Yunnan province.

The Lincang information office told China News Service on Monday that the bombing killed five people and injured eight others. The bodies of the five who died were cremated and the remains buried on Saturday.

The conflict in Myanmar, which has lasted for more than a month, "has impacted gravely on peace and stability in the China-Myanmar border area", Hong said at a daily news conference in Beijing.

Beijing has "lodged solemn representations through multiple channels" over the bombing, and Myanmar said it will launch a serious investigation and handle the incident appropriately, Hong added.

Jia Duqiang, an expert on Southeast Asian studies at the Chinese Academy of Social Sciences, said the investigation effort by Myanmar is expected and the cause of the tragedy deserves an official explanation.

The best way to prevent a similar occurrence "is to see the relevant parties in the conflict eyeing long-term stability and achieving a political settlement", Jia said.

Premier Li Keqiang said at a news conference on Sunday, "We have the responsibility and capacity to firmly safeguard stability in the border areas between the two countries, and protect the lives and property of our people."

The scene of the bombing has been sealed off to collect evidence, and financial help has been provided by the city for the bereaved families.

The Lincang information office said People's Liberation Army forces in the area, the Armed Police, public security and border defense authorities have further strengthened patrols, management and control over the border to prevent trespassing.

Lincang is increasing safety precautions and comforting residents, while Chinese national flags are "being installed on the rooftops of civilian residences and along the border by community-level officials and residents", the office added.

zhangyunbi@chinadaily.com.cn