BEIJING (Reuters) - China expressed anger on Tuesday after fighting between Myanmar soldiers and rebels unleashed a stray shell that flattened a house in its territory, and called for a cooling-off in tension after more than a month of strife.
Myanmar has accused Chinese mercenaries of fighting with ethnic Chinese rebels against the government in the northern region of Kokang and has sought China's cooperation to prevent "terrorist attacks" launched from its territory.
Fighting broke out last month between Myanmar's army and the Myanmar National Democratic Alliance Army (MNDAA), which groups remnants of the Communist Party of Burma, a powerful Chinese-backed guerrilla force that battled Myanmar's government before splintering in 1989.
Tens of thousands of refugees from the fighting have flooded into China's southwestern province of Yunnan, to the government's displeasure.
The shell that fell on Chinese soil on Sunday destroyed a house but did not cause casualties, Chinese Foreign Ministry spokesman Hong Lei told a daily news briefing.
"China has already expressed its serious concern to the Myanmar side, demanding they get to the bottom of what happened and take effective measures to prevent such an incident from happening again," Hong said.
The conflict was having a negative effect on stability and social order on the China-Myanmar border, he added. "We once again call on the parties in conflict to exercise restraint and alleviate the situation as soon as possible."
Eight Myanmar government soldiers were injured in fierce fighting over the weekend, the state-backed Global New Light of Myanmar reported on Tuesday.
The military used artillery and air strikes to capture hilltops near the China border that the MNDAA was using to launch attacks, the newspaper said.
Chinese and Myanmar envoys have been meeting in Beijing and in border towns to try and end the crisis, but with little apparent effect.