Ukraine's divisive opposition icon Yulia Tymoshenko completed an improbable return to politics Thursday by announcing plans to contest snap polls to replace the ousted pro-Russian president whose regime sent her to jail.

"I intend to run for president of Ukraine," the 53-year-old told reporters after gingerly walking into a press room with the help of a walking stick she uses due to chronic back pain.

European Union foreign policy chief Catherine Ashton on Thursday sounded a strong note of alarm over the escalation of violence in recent days in the capital of the Central African Republic.

"I am alarmed by the deteriorating situation in Bangui and the escalation of violence there since March 22," she said.

More than 251 Congolese refugees perished in the weekend sinking of a crowded boat on Lake Albert, between the Democratic Republic of Congo and Uganda, Kinshasa said Thursday.

Government spokesman Lambert Mende also declared three days of national mourning starting Thursday in the wake of Saturday's disaster.

A South Korean naval ship fired warning shots Thursday and seized a North Korean fishing boat intruding across the disputed Yellow Sea border, military officials said.

The vessel sailed a nautical mile south of the sea boundary at 5:26 pm (0826 GMT), prompting a South Korean patrol ship to take action, the South's defense ministry said.

Italy's navy said Thursday it had rescued 128 migrants from Egypt, Eritrea, Sudan and Syria from a boat crossing the Mediterranean which got into difficulty off the coast of Sicily.

The migrants, including eight women and 13 minors, were spotted by a helicopter patrolling the seas off Italy on Wednesday as part of an operation launched after two October shipwrecks in which hundreds drowned.

The biggest Muslim rebel group in the Philippines signed an historic pact Thursday to end one of Asia's longest and deadliest conflicts, promising to give up their arms for an autonomous homeland.

Following four decades of fighting that has claimed tens of thousands of lives, the Moro Islamic Liberation Front (MILF) signed the peace deal with President Benigno Aquino's government at a high-profile ceremony in Manila.

A Chinese man went on a killing spree following a dispute over family properties Thursday, leaving six people dead in a village outside Beijing, police said.

The 34-year-old, identified only by his surname Zhao, stabbed several people with a knife in Wanghua in Huairou, in the suburbs of the capital, before being overpowered by police, said the Beijing Public Security Bureau.

Several foreign aid workers were under police protection Thursday in unrest-torn western Myanmar, authorities said, after security forces fired warning shots to disperse a mob laying siege to the offices of an international humanitarian group.

Hundreds of local Buddhists massed around the offices of Germany-based medical aid group Malteser International late Wednesday in Sittwe, the capital of volatile Rakhine State, hurling stones and prompting police to escort at least eight staff to safety.

Attacks on villages in Darfur allegedly by a paramilitary unit are an "ugly blemish" on efforts to find a peaceful solution for the restive Sudanese region, Darfur's top peacekeeper says.

"The ongoing attacks on civilian villages and camps for internally displaced people, alleged to be carried out by the Rapid Support Forces, are a matter of concern and are an ugly blemish on our efforts to dialogue," said Mohamed Ibn Chambas, who heads the African Union-United Nations Mission in Darfur (UNAMID).

The U.N. Security Council will hold consultations Thursday over North Korea's recent ballistic missile tests, the council presidency said Thursday.

The closed door meeting has been requested by the United States, diplomats said.