Um ano de grande agitação no Iémen

ADEN, Dec 31 (Reuters) - Thousands of Yemenis began a 50 km (31 mile) march on Saturday to demand an end to a conflict which has forced nearly 100,000 people to flee southern Yemen, residents said, a day after seven militants were killed in fighting there with the army.

Up to 20,000 activists set out from the port city of Aden towards Zinjibar, the capital of Abyan province where the army has been battling Islamist militants suspected of having links with al Qaeda, residents said.

The marchers called on both sides to lay down their arms and demanded the government open the Aden-Zinjibar coastal highway, a key trade route which has remained closed during the conflict.

The militants and the Yemen-based regional wing of al Qaeda -- seen by the United States as the group's most dangerous branch -- have thrived during the instability caused by nearly a year of protests against the 33-year rule of outgoing President Ali Abdullah Saleh.

Top oil exporter Saudi Arabia, which shares U.S. concerns over more instability in a country sitting next to oil shipping routes, has backed a Gulf Arab plan to ease Saleh out of power.

Since Saleh handed over the reins to his deputy under the Gulf peace accord, a new government headed by an opposition leader has been formed. A presidential election is scheduled for February.

But the fighting against the Islamist militants in the south has continued, forcing about 97,000 people to flee. More than 300,000 others have been displaced by a conflict in the north and nearly 200,000 have sought refuge from Somalia, according to U.N. estimates.