SANAA, Yemen

Tribesmen threaten to join in battle against president

Thousands of tribesmen threatened Thursday to descend on Yemen’s capital to join the battle against forces loyal to President Ali Abdullah Saleh as the country slid deeper into an all-out fight for power. Government forces in Sanaa unleashed some of the heaviest shelling yet against their tribal rivals in a dramatic escalation of the conflict.

For months, youth-led protesters have tried to drive out Saleh peacefully. But their campaign has been overtaken and transformed into an armed showdown between Yemen’s two most powerful families, the president’s and the al-Ahmar clan. The al-Ahmar family heads the country’s strongest tribal confederation, which has vowed to topple Saleh after 33 years in power.

On Thursday, tribesman attacked security forces in the city of Taiz, apparently to avenge deaths of protesters there last week or to protect them from new crackdowns.

PESHAWAR, Pakistan

At least 72 killed in fighting near border of Afghanistan

At least 72 people have been killed in two days of intense fighting between Pakistani security forces and hundreds of militants who crossed from Afghanistan into northwest Pakistan, officials said.

Local officials and residents in Upper Dir, a remote valley that borders the Afghan province of Konar, said Pakistani troops regained control of the area after 36 hours of fierce clashes with heavily armed militants.

At least 27 Pakistanis, including four civilians, were killed in the fighting, as were 45 insurgents, local police officials said.

PORT-AU-PRINCE, Haiti

Clinics in Haitian capital report sharp rise in cholera

An international aid group says clinics in one section of the Haitian capital are seeing a sharp rise in cholera, with more than 300 new cases per day.

Oxfam said the spike in new cases is occurring in the densely populated Carrefour area west of downtown Port-au-Prince. The group reported Thursday that the number of new cases is more than three times what it saw back when the disease first surged in the fall. Oxfam and other groups are stepping up cholera treatment and prevention in Haiti as the waterborne disease increases amid heavy rain.

Haiti’s health ministry says cholera has killed more than 5,300 people and sickened more than 320,000 since the outbreak began in October.

TOKYO

Radioactive water presents new contamination threat

Radioactive water accumulating in Japan’s crippled Fukushima plant may start overflowing from service trenches in five days, potentially increasing the contamination from the worst nuclear crisis since Chernobyl.

Tokyo Electric Power Co. has been manually pumping water into overheating reactors since cooling systems broke down and much of that has overflowed into basements and trenches. The water is rising at a rate that means it will overflow as early as Monday, Bloomberg calculations from the company’s data show.

“There is still a risk of radioactive water leaking into the sea,” Hikaru Kuroda, an official at the utility known as Tepco, said Thursday. “We may have between five and seven days before the water levels reach the top of the trenches.”