German Chancellor Angela Merkel's party was in the lead Sunday after the first state poll of a general election year, initial results showed, but the race for a ruling coalition rested on a knife-edge.

Preliminary results from Lower Saxony on public television showed Merkel's Christian Democrats leading with around 36 percent and their current coalition partners, the Free Democrats, with about 10 percent. The Social Democrats had about 32 percent and their favored allies the Greens 13 percent.

President Barack Obama took the oath of office Sunday to begin a second term threatened by strife at home and abroad and amid inaugural rituals lacking the hope and historic promise of 2009.

Obama, with a slight smile, took the oath at an intimate, private ceremony in the Blue Room of the White House lasting less than a minute, raising his right arm and placing his left hand on a family Bible.

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.

Police in Nigeria have found at least 15 unidentified corpses floating on a river in southeast Anambra state, officials said Sunday, while local media said the number of bodies could be much higher.

"I don't know the exact number of bodies but I have seen at least 15 corpses floating on the river," Anambra police commissioner Bala Nasarawa said in a television interview after visiting the scene.

Notorious Russian crime boss Aslan Usoyan was buried in a tightly controlled ceremony in Moscow on Sunday, after efforts to fly his body to his hometown in Georgia fell through.

A sniper fatally shot Usoyan in the neck in central Moscow on Wednesday. Known in the mafia world as "Grandpa Hassan," Usoyan, 75, was the head of a gang that is reportedly the most powerful in the former Soviet Union.

U.S. Vice President Joe Biden re-took the oath of office Sunday as Barack Obama officially begins his second term, a day ahead of public festivities planned for Monday.

Biden placed his hand on a thick and weathered-looking bible held by his wife, Jill, and pledged to "support and defend the constitution of the United States against all enemies, foreign and domestic."

French forces are advancing towards Mali's Islamist-held north after taking up positions in the towns of Niono and Sevare, a spokesman for the French military operation codenamed Serval said Sunday.

"The deployment towards the north of the forces of Operation Serval, which began 24 hours ago, is on course with troops inside the towns of Niono and Sevare," Lieutenant Colonel Emmanuel Dosseur told reporters.

Islamists holding foreigners hostage at a gas plant in the Algerian desert executed nine Japanese captives during a 72-hour stand-off with the military, Algerian witnesses said on Sunday.

"In all nine Japanese were killed," one witness identified as Brahim told AFP a day after special forces swooped on the In Amenas facility to end the deadly siege.

Security forces found the bodies of 25 hostages on Sunday as they combed a desert gas plant after a deadly stand-off with Islamists, and witnesses said nine Japanese captives had been executed.

Citing security sources, Anis Rahmani of private television channel Ennahar told Agence France Presse the army discovered "the bodies of 25 hostages" as they secured the sprawling In Amenas Sahara site.

French Foreign Minister Laurent Fabius said Sunday that Russia had offered to help transport French troops and supplies to Mali and that Canada was to help to bring African troops to the country.

Asked on Europe 1 radio about how African troops would be transported, Fabius said "there is transportation that will be partly by the Africans themselves, partly by the Europeans and partly by the Canadians."