HARI SREENIVASAN: A major aftershock hit Japan's already devastated northeastern coast today and touched off a new scare. The quake was centered about 40 miles east of the stricken city of Sendai, and it triggered a brief tsunami alert.
We have a report narrated by Paul Davies of Independent Television News.
PAUL DAVIES: A fixed camera on a tower block captures the moment the city of Sendai begins to shake again. The lights go out. And people all over Japan must have been thinking, not again.
There have been thousands of aftershocks since last month's earthquake, but this was something else. Inside a block of flats, the power fails. Listen to the sound of walls vibrating. There was an instant tsunami warning.
WOMAN (through translator): If you're still around the close area, please do flee to the high ground as soon as possible.
PAUL DAVIES: Though the warning was later lifted when it was realized there would not be a second deadly wave to add to this destruction.
Among those who took shelter in Sendai was a doctor who had been treating victims of the original quake.
DR. UNNI KRISHNAN: Suddenly, the building started shaking, shaking and swinging. And I just pulled out a (INAUDIBLE) that I kept on the table, put it on my head, and I went below the table to protect my head in case things started falling down.
PAUL DAVIES: The aftershock, measured at a powerful 7.1, appears to have been just a nasty reminder of last month's disaster. Japanese authorities say there is no new damage to their nuclear plants, only to the nerves of those who have learned enough about earthquakes to know when something feels like the real thing.
HARI SREENIVASAN: The aftershock also disrupted gas and water service in parts of the quake zone. And it caused buildings to sway as far south as Tokyo, 200 miles away.
Rebels in Eastern Libya reported NATO airstrikes mistakenly hit their positions again. Today, two of the rebels died and more than a dozen others were injured in the attack near Brega. And it would mark the second such friendly fire attack in less than a week.
Meanwhile, in Washington, the head of the United States Africa Command said the fighting in Libya is becoming a stalemate. But General Carter Ham warned against arming the rebels without knowing more about them.
GEN. CARTER HAM, U.S. Africa Command: I think, not knowing who the opposition forces are, are they trustworthy, we have seen certainly media reporting of extremist organizations at least espousing support for the opposition. And we need, I think, necessarily to be careful about providing lethal means to a group, unless we are assured that those U.S.-provided weapons would not fall into the hands of extremist organizations.
HARI SREENIVASAN: Gen. Ham also said an international ground force could bolster the rebels. President Obama has said there will be no American troops on the ground in Libya.
And, in another development, the news organization GlobalPost reported today that pro-Gadhafi forces have detained freelance correspondent James Foley and several other foreign journalists.
NATO and Afghan troops killed a border policeman today, after he shot dead two American soldiers on Monday. They had been training Afghan forces at a base in Faryab in the northern part of Afghanistan. Today's joint operation took place in that same region.
The U.S. is willing to keep troops in Iraq beyond a Dec. 31 deadline to withdraw if the Iraqis ask. Defense Secretary Robert Gates raised that possibility today during a visit to Baghdad. He also said the Iraqis have to act soon, so U.S. officials can start planning. At the same time, an Iraqi government spokesman said the presence of these forces is not suitable for Iraq.
In Brazil, a gunman opened fire at an elementary school in Rio de Janeiro today, and killed at least 11 students before he turned the gun on himself. Aerial footage showed the streets outside clogged with emergency vehicles and family members awaiting news. In addition to the dead, at least 18 people were wounded.
China has confirmed it detained the outspoken government critic Ai Weiwei this week. The international -- the internationally acclaimed conceptual artist has been in custody since Sunday, and human-rights groups and other countries have called for his release.
But, today, a Chinese Foreign Ministry spokesman said he's being held for unspecified economic crimes. The spokesman warned other governments not to meddle in the case.
HONG WEI, Chinese foreign ministry (through translator): China is a country ruled by law. Other countries have no right to interfere with Chinese inner affairs. China is willing to discuss relevant issues with other countries based on equality and mutual respect. We hope relevant countries can respect the decision of China.
HARI SREENIVASAN: The Chinese government has begun a systematic crackdown on dissidents and activists since the political upheavals in the Middle East and North Africa.
The World Health Organization warned today that more and more infections are becoming resistant to antibiotics. The U.N. Agency reported there were more than 440,000 cases of drug-resistant tuberculosis last year. And diseases such as shigella, gonorrhea and malaria are becoming harder to treat. The WHO blamed improper use of medicines and the use of antibiotics in livestock. It also said a new drug-resistant gene is widely circulating in India and Southwest Asia and could quickly spread worldwide.
Portugal has formally submitted its request for a financial bailout from the European Union. It is the third Eurozone country, after Greece and Ireland, to ask for such aid. Portugal has struggled to tackle rising debts amid a political crisis. The government was dissolved last month after Parliament rejected austerity measures.
On Wall Street today, stocks fell sharply after initial reports of the latest aftershock in Japan. They recovered most of the losses as the day progressed. The Dow Jones industrial average finished with a loss of 17 points to close at 12,409. The Nasdaq fell three points to close at 2,796.
Those are some of the day's major stories.