U.N. Secretary-General Ban Ki-moon has called for a "serious effort" to end the conflict raging in northern Myanmar, where ethnic minority Kachin rebels accused the military of breaking its ceasefire.

Prime Minister Thein Sein's reformist government announced on Friday that it was ending a military offensive against the Kachin rebels, but fresh fighting erupted over the weekend.

Kachin ethnic minority rebels in war-torn northern Myanmar accused the military of launching a fresh attack Sunday, just days after a ceasefire pledge by the country's reformist government.

The clashes came despite a new offer by President Thein Sein of peace talks to end Myanmar's last active civil war, which has marred widespread optimism about the regime's dramatic political reforms.

U.S. nuclear officials have held talks with their counterparts in Myanmar, weeks after the former pariah nation agreed new safeguards allowing inspections of suspected atomic sites, the U.S. Embassy said Wednesday.

Myanmar, also known as Burma, was suspected of pursuing military and nuclear cooperation with Pyongyang during long years of junta rule that ended last year, prompting an easing of many international sanctions including by the U.S.

Kachin rebels on Monday said three civilians were killed and six wounded in the first attack by Myanmar forces on their northern stronghold, as fighting escalates in the country's last active civil war.

Three shells landed in "the heart of Laiza" town, the Kachin Independence Army's base near the Chinese border, early Monday, Colonel James Lum Dau, spokesman for the KIA's political wing, told Agence France Presse.

With its glossy pages of pouting models and racy romance tips, Myanmar's first sex education magazine has got the usually demure nation hot under the collar as it explores new-found cultural freedom.

"Hnyo" has sparked fevered debate since hitting Myanmar's bookstores in November, becoming a must-read among the young and curious, just a few months after the end of direct censorship in the former junta-ruled nation.

Around 400 Rohingya migrants discovered in a raid on a camp hidden in a remote rubber plantation in southern Thailand will be deported back to Myanmar, Thai police said Friday.

The group, 378 men, 11 women and 12 children, were found in a makeshift shelter in the plantation in Songkhla province where they had languished for three months waiting to be trafficked to a "third country", local police said.

Myanmar on Thursday denied accusations it had used chemical weapons against ethnic minority rebels in the northern state of Kachin, where an escalating conflict has overshadowed wider political reforms.

"Our military never uses chemical weapons and we have no intention to use them at all. I think the KIA (Kachin Independence Army) is accusing us wrongly," presidential spokesman Ye Htut said.

A British-led excavation team hunting for dozens of rare Spitfires in Myanmar said Wednesday they were confident about recovering the World War II-era planes after finding a crate buried in the ground.

Project leader David Cundall, who has compared the rumored hoard to the 1922 discovery of Egyptian pharaoh Tutankhamun's tomb, said a box found in the Kachin state capital Myitkyina appeared to contain man-made objects.

Aung San Suu Kyi's opposition Monday said it plans to hold its first ever national conference next month, in the latest sign of the party's mainstream role after decades of repression under Myanmar's former junta.

"We have been trying to convene such a nationwide conference for more than 20 years," Ohn Kyaing, a spokesman for the National League for Democracy (NLD), told AFP.

Myanmar said Friday it will allow private daily newspapers starting in April for the first time since 1964, in the latest step toward allowing freedom of expression in the long-repressed nation.

The Information Ministry announced on its website that any Myanmar national wishing to publish a daily newspaper will be able to submit an application in February. New papers will be allowed to begin printing April 1 in any language.