Thailand and Cambodia said Thursday they had agreed to end fierce fighting on their shared border after seven days of clashes that have left 15 dead, Agence France Presse reported.

"After discussions by the military on both sides this morning, there is a ceasefire agreement... border checkpoints will be reopened and villagers will start to return home," said Thai government spokesman Panitan Wattanayagorn.

State television said renegade warlord Ibrahim "IB" Coulibaly, a two-time coup plotter who began the pro-democracy battle for Abidjan, was killed in fighting Wednesday night with one-time allies turned enemy, Associated Press reported.

He died after his top aide said Coulibaly's troops were waiting for U.N. peacekeepers to disarm them.

Three people were killed and 15 others wounded Thursday when a bomb hit a bus ferrying Pakistani naval officials to work in the port city of Karachi, the third such attack in days, Agence France Presse reported.

The bomb was planted on the roadside in busy Faisal Avenue and detonated remotely as the bus drove past in Pakistan's politically tense economic capital, used by NATO to ship supplies to troops in Afghanistan.

Deadly tornados and flash floods flattened buildings and overturned vehicles overnight as major storms churned through the United States, with the death toll surpassing 160 people.

The severe weather killed 128 people in Alabama on Wednesday alone, authorities said, and President Barack Obama said Washington would be rushing search and rescue assistance to the battered southeastern state.

President Barack Obama will Thursday name CIA director and Washington power player Leon Panetta defense secretary, reshuffling his security team at a pivotal moment for U.S. military strategy.

Panetta, 72, will replace Robert Gates, who retires as Pentagon chief on June 30, and Obama plans to recall talismanic General David Petraeus from Afghanistan, who will end a decorated military career to lead the CIA.

Eight NATO troops and a contractor were killed when an Afghan pilot opened fire on Wednesday after a row at a Kabul training center in one of the deadliest such attacks since the U.S.-led invasion in 2001.

The killings appeared to stem from an argument rather than terrorism, but served to highlight the prevailing insecurity in Afghanistan, 10 years after foreign troops ousted the Taliban from power.

At least six people were killed and 60 others injured Wednesday when a train carrying Chinese tourists was hit by a falling tree at a popular mountain spot in central Taiwan, officials said.

The sightseeing train was traveling along Mount Ali when the tree trunk fell, causing four carriages to derail and overturn, said an official at the forestry bureau, which supervises the area.

Malawi has declared Britain's top diplomat to the southern African nation persona non grata after his criticism of the president was leaked to the press, diplomats said Wednesday.

"I am sorry to pass on the news that the Malawi Government has officially informed the Foreign and Commonwealth Office today (Tuesday) that Fergus (Cochrane-Dyet) is being declared persona non grata," British high commission vice-consul Lindsay McConaghy wrote in a memo, a copy of which was seen by Agence France Presse.

Hopes of an imminent ceasefire between Thailand and Cambodia faded Wednesday after Bangkok pulled out of talks with its neighbor and deadly border clashes entered a sixth day.

Cambodia's prime minister called for a truce in the bloodiest fighting between the two countries in decades, which has left 14 people dead and forced tens of thousands of civilians to flee cross-border shelling.

Taiwan's main opposition party said Wednesday it will nominate ex-vice premier Tsai Ing-wen for next year's presidential election, the first woman in Taiwan's history to run for the post.

Tsai, 54, won the pro-independence Democratic Progressive Party's (DPP's) primary to secure her candidacy against two senior party members, said acting chairman Ker Chien-ming.