Myanmar extended a state of emergency in a conflict wracked northern region near China Friday, with the defence minister arguing that continued military control of the area was necessary to ensure "peaceful relations" across the border.

Fighting between government troops and ethnic Chinese rebel fighters has raged in the Kokang region of Shan state since early February, raising fears over the country's peace process and causing tens of thousands of people to flee, many into China.

Myanmar air strikes have also drifted into Chinese territory, killing several civilians and prompting a rebuke from Beijing which scrambled its fighter jets.

A state of emergency giving the military sweeping powers has been in place in Kokang since February and Myanmar's parliament on Friday approved an extension, following an application from defence minister Lieutenant general Wai Lwin.

He told the legislature that the move was needed to ensure "stability" in the region, particularly as the country prepares for crucial elections later this year as it emerges from decades of military rule.

"That's why I have requested 90 more days of military administration; it is needed to be able to continue working for border security and peaceful relations with our neighbouring country," he said.

Of the nearly 90,000 people who have fled the region, only some 11,000 have returned, he said.

Conflict in the isolated mountainous region has overshadowed wider efforts to secure a nationwide ceasefire with a host of other rebel groups -- excluding the Kokang.

Myanmar has seen decades of conflict in its ethnic minority border areas, with insurgencies driven by regional demands for greater political autonomy as well as tussles over natural resources.

In March the United Nations hailed a draft ceasefire document as "historic", but efforts to ink a full deal have yet to bear fruit and have been shaken by on going conflicts in Shan state and neighbouring Kachin.

Although the Kokang rebels, who were driven out of Myanmar by the army in 2009 before suddenly returning in February, are not directly involved in peace talks, the ongoing fighting has drawn condemnation from the coalition of armed groups at the negotiating table.

Scores have died in the Kokang unrest, although precise numbers of military and civilian casualties are unknown and attacks on humanitarian convoys have hampered relief efforts.

Myanmar government-run media initially carried detailed daily updates of the conflict against the Myanmar Nationalities Democratic Alliance Army (MNDAA), the main insurgent group of the Chinese-speaking Kokang.

But information has recently dried up as clashes continue.