A 5.5-magnitude earthquake struck off the east coast of Japan on Monday, the U.S. Geological Survey reported, but no tsunami warning was issued.

The quake hit at a depth of 26 kilometers (16 miles) at 3:13 am (1813 GMT Sunday), about 324 kilometers east of the town of Namie, the USGS said.

Twelve people were killed in fierce clashes over the weekend between vigilante groups and former rebels in the western Central African town of Bouar, according to a military source Sunday.

The updated death toll came after militias armed with machetes encircled Bouar, a town some 400 kilometers (250 miles) northwest of the capital Bangui on Saturday morning, the same source said on condition of anonymity.

The National Security Agency denied German press reports Sunday that President Barack Obama was personally informed of U.S. spies tapping German Chancellor Angela Merkel's phones.

NSA chief General Keith Alexander "did not discuss with President Obama in 2010 an alleged foreign intelligence operation involving German Chancellor Merkel, nor has he ever discussed alleged operations involving Chancellor Merkel," spokeswoman Vanee' Vines said.

Thousands of ethnic Hungarians staged rallies in Romania on Sunday to call for autonomy for the Szeklers' Land, home to most of their minority.

Romanian police said some 15,000 people had taken part in peaceful demonstrations across the country's central Transylvania region, while organizers put the turnout at around 100,000.

The Tehran municipality has removed anti-American posters from the streets of the capital which questioned U.S. honesty in nuclear talks with Iran, media reported on Sunday.

The move comes as President Hassan Rouhani, a reputed moderate, has made fresh overtures to the West, including direct talks between U.S. and Iranian officials, and ahead of the 34th anniversary of the U.S. embassy seizure in Tehran.

Member states of the International Atomic Energy Agency should work together to boost security around radioactive sources, the body's deputy director said on Sunday.

"We should all work together ... to achieve one common goal: protecting people, society and the environment from the harmful effects of ionizing radiation that may occur through the inadvertent or malicious use of radioactive sources," Denis Flory said.

Brazil fired an intelligence officer last year believed to have disclosed government secrets to a CIA agent, O Estado de Sao Paulo newspaper said Sunday.

The newspaper said that the Brazilian agent provided the Central Intelligence Agency around mid-2012 with information pertaining to a border standoff between Brazil and its neighbors Paraguay and Argentina.

U.S. intelligence is better than in Europe, and snooping at the heart of a widening scandal helps keeps the world safe, a top U.S. lawmaker declared Sunday amid a widening spying row.

House Intelligence Committee Chairman Mike Rogers also suggested there was nothing surprising in revelations that the United States was monitoring communications of several dozen world leaders and ordinary citizens, and blamed the news media for getting the story wrong.

A roadside bomb blast on Sunday killed at least 18 civilians, mostly women, as they were heading to a wedding party in central Afghanistan, provincial officials said.

"A roadside bomb planted by the enemies of Afghanistan in Andar district of Ghazni province hit a civilian vehicle around 4:30pm," Mosa Khan Akbarzada, Ghazni provincial governor, told Agence France Presse.

A Tanzanian officer with U.N. forces operating alongside government troops in the eastern Democratic Republic of Congo was killed in fighting with rebels on Sunday, the U.N. mission said.

"A Tanzanian lieutenant with the (U.N.) intervention force was killed as the brigade was deployed with the army in Kiwanja (near the regional capital Goma)," an officer with the U.N. mission known as Monusco told Agence France Presse.