The United States reacted with concern Wednesday after Iran unveiled a new uranium production facility and two extraction mines, but said it had not been "blindsided" by the news.

Iranian President Mahmoud Ahmadinejad hailed the advances on Tuesday and boasted of mastery over "the entire chain of nuclear energy" only days after talks with world powers on its disputed nuclear program ended in deadlock.

Four Kenyans were among the 12 people shot dead by gunmen who attacked a United Nations convoy in South Sudan on Tuesday, officials said Wednesday.

Five Indian peacekeepers were also killed when some 200 attackers -- some armed with rocket-propelled grenades -- ambushed the convoy in the troubled eastern region of Jonglei.

A Pakistani policeman was shot dead and another was wounded on Wednesday while escorting a polio vaccination team in the country's northwest, local officials said.

No one has claimed responsibility for the killings, but the Pakistani Taliban last year banned polio vaccinations in the tribal region of Waziristan, alleging the campaign was a cover for espionage.

The use of the death penalty is broadly diminishing around the world although a handful of countries that had not used capital punishment for several years resumed executions in 2012, Amnesty International said on Wednesday.

India, Japan, Pakistan and Gambia, all countries which had not put people to death for some time, resumed executions last year, and there was an "alarming escalation" in executions in Iraq, the rights group said in its annual survey of the death penalty.

At least two people were killed and many feared injured when a Bangalore-bound train derailed in southern India on Wednesday morning, a railways official told Agence France Presse.

V.J. Accamma, a spokesman for Southern Railways, confirmed the death of at least two people in the accident, which occurred just after dawn in the small village of Chitteri in the southern state of Tamil Nadu.

As France begins withdrawing its troops from Mali, a top U.S. defense official has said a U.N.-mandated African force was "incapable" of taking over the battle against Islamist extremists.

Paris, which sent 4,000 troops to Mali in January to block a feared advance on the capital Bamako by Islamist fighters, said Tuesday it had pulled out its first batch of soldiers preparing to hand over to an African force of 6,300 in the coming weeks.

South Korea raised its military watch alert to "vital threat" Wednesday before an expected North Korean missile launch, as U.N. chief Ban Ki-moon warned the Korean peninsula may be slipping out of control.

The North last week, told foreign diplomats in Pyongyang they had until April 10 to consider evacuation, fueling speculation a launch was planned between Wednesday and the April 15 birthday celebrations for late founder Kim Il-Sung.

A four-year-old boy in New Jersey shot and wounded a six-year-old friend in the head Tuesday, police said, the second such accident involving children in a day.

Police in the town of Toms River said the young boy took a .22 caliber rifle and shot his friend at a distance of about 14 meters (45 feet). It was unclear why the weapon discharged.

The Chinese human rights activist at the center of a diplomatic crisis a year ago on Tuesday accused Beijing of reneging on the agreement that freed him and urged the United States to intervene.

Chen Guangcheng, a blind self-taught lawyer who infuriated authorities by exposing forced abortions, dramatically escaped house arrest in April 2012 by scaling the walls of his home and taking a getaway car to the U.S. embassy.

At least 14 people were hurt Tuesday in what appeared to be a mass stabbing at a community college in the U.S. state of Texas and a suspect is in custody, police said.

The apparently random attack occurred at the CyFair campus of Lone Star College near Houston.