France has deployed tens of thousands of security forces in the hunt for two brothers accused of killing 12 people at the offices of the satirical magazine Charlie Hebdo, a hunt which is now focused on a forest and several woodland villages northeast of Paris.

French Interior Minister Bernard Cazeneuve announced that 88,000 forces had been mobilized and that an international counterterrorism meeting would take place in Paris on Sunday. Cazeneuve also announced that nine people had been detained in connection with the alleged attackers, Cherif and Said Kouachi.

Helicopters were employed in the house to house search of the villages of Corcy and Longpont. But officers pulled back late Thursday as darkness set in without having pinpointed the location of the terrorists, counter to earlier reports.

"We have not found them, there is no siege," said an interior ministry source.

European and United States sources close to the investigation divulged that one of the brothers, Said, had been trained in Yemen by al Qaeda in the Arabian Peninsula (AQAP). A Yemini official confirmed that the government was aware of a possible link between Kouachi and AQAP, and was investigating the connection. Said's brother Cherif previously served 18 months in jail in 2005 for involvement in the insurgency in Iraq.

"Vive la France!"

Al Qaeda's North Africa branch hailed the assault on the satirical cartoonists, who had more than once mocked Islam and drawn depictions of the Prophet Mohammad, calling the gunmen "knights of truth."

But the rest of the world showed their solidarity by holding vigils and uniting under the motto "Je suis Charlie" or "I am Charlie," and many newspapers republished Charlie Hebdo cartoons in a gesture of support.

US President Barack Obama made an unannounced visit to the French Embassy in Washington on Thursday. He spoke with the ambassador and signed a condolence book, writing: "As allies across the centuries, we stand united with our French brothers to ensure that justice is done and our way of life is defended...Vive la France!"

French President Francois Hollande had declared Thursday a national day of mourning, only the fifth in the last five decades. The Eiffel Tower shut off its lights.

The government has called for large demonstrations across the country on Sunday and has ordered flags on public buildings to fly at half-mast for three days.

es/jm (AFP, Reuters)