A bomb exploded inside a grocery store frequented by foreigners on Friday in Kabul, killing at least eight people and injuring others, police and eyewitnesses said.

Three foreigners and a child were among the dead, Kabul Police Chief Mohammad Ayub Salangi told reporters at the scene.

Anti-apartheid icon Nelson Mandela was starting his third day in a Johannesburg hospital Friday, but the South African government says there is no need to panic.

In a statement late Thursday, Deputy President Kgalema Motlanthe offered no specifics on why Mandela, 92, was taken to the hospital Wednesday, but said he was undergoing specialized tests.

At least 16 people were killed when a fire broke out overnight on an Indonesian ferry with more than 400 people on board, the transport ministry said Friday.

The ferry caught fire in the Sunda Strait between the islands of Java and Sumatra, about three kilometers (two miles) from the port of Merak at the westernmost tip of Java, at around 3:30 am.

A small blast shattered two windows but caused no injuries at a hotel near where top business and political leaders are attending the World Economic Forum, Swiss police said Thursday.

The explosion happened in a storage room of the Posthotel Morosani shortly after 9 a.m. local time (0800 GMT) Thursday, regional police spokesman Thomas Hobi told the Associated Press.

Several international flights to and from the resort island of Bali were cancelled or diverted Thursday to avoid dangerous ash spewing from an Indonesian volcano, officials said.

Ash from rumbling Mount Bromo, a popular attraction in East Java province, had spread to the island popular with foreign tourists and surfers.

An explosion likely caused by a methane gas buildup ripped through an underground coal mine in Colombia during a shift change Wednesday, killing 21 workers, officials said. A similar fatal blast occurred at the same mine four years ago.

Five of the victims died at the mine's entrance and by afternoon two bodies had been removed from the mine with another 14 left to recover, said the provincial Colombian Red Cross director, Johel Enrique Rodriguez.

Russia's upper house of parliament Wednesday ratified the new U.S. nuclear disarmament treaty, the final step in approving the first nuclear pact between the two former Cold War foes in 20 years.

All 137 senators in the Federation Council upper house approved the new START treaty, which U.S. President Barack Obama and his Russian counterpart Dmitry Medvedev signed in Prague on April 8, 2010.

Pleading for unity in a newly divided government, President Barack Obama implored Democratic and Republican lawmakers to rally behind his vision of economic revival for an anxious nation, declaring in his State of the Union address Tuesday night: "We will move forward together or not at all."

The president unveiled an agenda of carefully balanced political goals: a burst of spending on education, research, technology and transportation to make the nation more competitive, alongside pledges, in the strongest terms of his presidency, to cut the deficit and smack down spending deemed wasteful to America. Yet he never explained how he'd pull that off or what specifically would be cut.

At least four people were killed and 15 injured when a bomb exploded on a crowded bus in the Philippine capital's financial district on Tuesday, authorities said.

The attack occurred two months after the United States and several other Western governments warned a terrorist attack in Manila was imminent, and followed a bus hijacking last year that left eight Hong Kong tourists dead.

British fighter jets escorted an Etihad airlines jet to land at London's Stansted airport on Monday after it was diverted because of a passenger making threats, officials said.

A 37-year-old British national was arrested after the flight bound for London's Heathrow Airport from Abu Dhabi landed, but the incident was not believed to be terrorism-related, said police.