Suspected Boko Haram gunmen attacked a market in restive northeastern Nigeria, killing five and injuring many more, witnesses said on Monday.

More than 30 attackers armed with guns, explosives and knives stormed the market in Borno State, where a state of emergency is in place, they said.

The U.S. Supreme Court appeared to be preparing Monday to limit the president's power to appoint high-level judges and officials while Congress is in recess.

By law, the president has the right to choose the nominees and lawmakers have the right to offer "advice and consent."

U.S. President Barack Obama on Monday urged Congress to give diplomacy a chance in resolving the Iranian nuclear issue, with some American lawmakers urging fresh sanctions on Tehran.

Obama made the remarks following a meeting with Spanish Prime Minister Mariano Rajoy in the Oval Office.

U.S. President Barack Obama will travel to Toluca, Mexico on February 19 for a North American leaders summit, the White House said Monday.

The meeting will be hosted by Mexico's President Enrique Pena Nieto and will also include Canadian Prime Minister Stephen Harper.

European Union foreign policy chief Catherine Ashton said in Kuwait City on Monday she plans to visit Iran within weeks, two days after Tehran invited her to the country.

"I read with interest the invitation to visit Tehran and it is my intention to do so in the course of the next weeks," Ashton told a press conference after talks with Kuwait's Foreign Minister Sheikh Sabah Khaled al-Sabah.

Valerie Trierweiler, the long-term girlfriend of French President Francois Hollande, was to remain in hospital on Monday where she was admitted after reports emerged her partner was having an affair with an actress.

Trierweiler, 48, was taken to hospital suffering from stress on Friday, and was initially expected to check out on Monday.

Former U.S. defense secretary Robert Gates insisted Monday his new memoir is "even-handed" and accused opponents of President Barack Obama of misrepresenting it to score political points.

Gates' book has been widely portrayed as an attack on Obama's war leadership, but the author himself said he had in fact agreed with the major decisions the US president made on Afghanistan.

At least 127 people have been killed and some 100 others wounded in violence in the Central African Republic over the past three days, the country's Red Cross office said on Monday.

The president of the country's Red Cross Antoine Mbaobogo said 25 bodies had been collected in Bangui, 97 in the north-western town of Bozoum and five in M'Bata in the south-west.

Pope Francis on Monday issued his strongest condemnation yet of abortion, calling it a symptom of a "throwaway culture" that placed too little value on human life.

The pope, who has focused more on social issues such as poverty than on abortion since becoming pontiff in March, said it was "frightful" to think about the early termination of pregnancy.

Nuclear experts will visit Iran on Saturday to prepare for a deal curbing the Islamic republic's atomic program two days before it takes effect, an official in Tehran said.

The International Atomic Energy Agency "experts will visit Tehran on January 18 to prepare for the implementation of the Geneva agreement," IRNA news agency quoted Behrouz Kamalvand, spokesman for Iran's Atomic Energy Organization, as saying on Monday.