Russia's Vladimir Putin has agreed to a proposal from Angela Merkel to set up a contact group on Ukraine, the German government said Sunday.

The German chancellor put the proposal to Putin in a telephone conversation late Sunday in which she also "accused the Russian president of violating international law with the unacceptable Russian intervention in Crimea," said a government statement.

Former oil tycoon Mikhail Khodorkovsky, who was freed by Moscow last month after a decade in jail, vowed Sunday to fight for Russian political prisoners from his new base in Switzerland.

"You can't live with peace of mind when you know there are political detainees rotting in prison," Khodorkovsky told Swiss public television SRF on the train that took him from Berlin to Basel.

Kremlin critic Mikhail Khodorkovsky is set to reunite with his wife Inna and their three children in Berlin on Christmas Eve after spending 10 years in a Russian jail, his spokeswoman said on Tuesday.

"The family is coming today," spokeswoman Olga Pispanen told AFP. "They have not been together for 10 years."

The German government will study whether U.S. fugitive leaker Edward Snowden can be questioned in Russia, as it sought Wednesday to calm tensions with London and Washington over spy allegations.

Members of a German parliamentary committee overseeing the secret services agreed to ask the government to examine the possibility of Snowden answering questions in Moscow, provided it does not create "difficulties" for him there, its chairman Thomas Oppermann said.

U.S. intelligence leaker Edward Snowden is ready to talk with German prosecutors in Russia, his lawyer said on Friday, after the fugitive met a German lawmaker over his evidence that Washington spied on Chancellor Angela Merkel.

The former National Security Agency (NSA) contractor, who was also due Friday to begin work at an undisclosed Russian Internet firm, was granted asylum in Russia in August to the fury of the United States, where he faces trial.

Germany's foreign ministry confirmed Monday that a security official at its embassy in Yemen has been killed but denied reports of an attempted kidnapping of its ambassador.

Earlier reports had said the envoy herself had been the target of a failed abduction attempt Sunday, but the foreign ministry then told Agence France Presse that Ambassador Carola Mueller-Holtkemper was outside the country at the time.

A mysterious "forest boy" who turned up in Berlin in 2011 claiming to have lived in the woods for years was sentenced to perform community service Thursday by a German court.

In a tale that captured the world's imagination, the then teenager appeared at Berlin city hall in September two years ago saying that his first name was Ray and that he had lived in the woods with his father for five years.

Berlin Wednesday kicks off the reconstruction of its palace, a divisive 590-million-euro ($783 million) project to recreate the baroque architectural jewel whose post-war remnants were razed by communist leaders.

President Joachim Gauck will attend the official laying of the foundation stone for the Berlin Palace, on the city's legendary leafy axis, Unter den Linden, which Prussian princes once called home.

The opening this month of the first life-sized Barbie Dreamhouse in Europe may be the fantasy of many a little girl, but Berlin feminists are mobilizing against what they call a sexist icon.

With her ironed-straight blond tresses, doe-like baby blue eyes, blinding smile and super-human measurements, the mistress of the giant Barbie mansion has become a lightning rod ahead of the May 16 inauguration.

The discovery of an unexploded World War II bomb unearthed near Berlin's main train station snarled rail and road traffic in the German capital Wednesday, authorities said.

"The bomb was found yesterday (Tuesday) afternoon on property belonging to the rail company," a police spokesman told AFP, adding that sappers planned to defuse it Wednesday.