Myanmar on Tuesday sentenced seven Muslims to prison terms ranging from two to 28 years in connection with religious violence in March that left dozens of people dead, a justice official said.

The defendants, who were spared the death penalty, were accused of the murder of a Buddhist monk in the central town of Meiktila that sparked unrest across the region, mostly targeting Muslims.

A roadside bomb in western Afghanistan and clashes in the volatile south left eleven police officers dead, officials said Tuesday.

The bomb killed six police guards in Herat province on Tuesday as they traveled to a hydroelectric dam that is under protection from insurgent attack.

A 6.0-magnitude earthquake struck Russia's Kamchatka Peninsula early Tuesday, followed by a series of strong after-shocks, the US Geological Survey reported.

The first quake struck at a depth of 33 kilometers (20 miles) at 0155 GMT, 136 kilometers east-southeast of the Russian city of Petropavlovsk-Kamchatsky, the USGS reported.

Rescuers recovered another four bodies from a collapsed underground room at a giant U.S.-owned gold and copper mine in Indonesia, bringing the confirmed death toll to 21, mine officials said Tuesday. Seven others were believed buried under the rubble.

The Big Gossan underground training facility at the PT Freeport Indonesia mine collapsed last week when 38 workers were undergoing safety training. Ten injured miners were rescued.

A powerful tornado swept through an Oklahoma City suburb on Monday, tearing down blocks of homes, two schools and leaving at least 91 people dead, including 20 children, local officials said.

The state medical examiner's office released the latest death toll but the number was climbing rapidly, as emergency crews combed through smashed homes and the collapsed remains of an elementary school in Moore, Oklahoma.

U.S. President Barack Obama on Monday threw his support behind Myanmar President Thein Sein in his drive to reform a former pariah state but warned that a wave of violence against Muslims must stop.

As his guest became the first leader of his country in almost 50 years to visit the White House, Obama praised Myanmar's journey away from brutal junta rule and promised Washington would offer more political and economic support.

North Korea released 16 Chinese fishermen and their boat Tuesday, Chinese state media said, after reports that armed assailants had taken the sailors hostage fueled strains between the neighbors.

"All the fishermen with the boat are safe on their way back," China's Xinhua news agency said, citing a Chinese embassy official in Pyongyang it said had heard the news from the shipowner.

Nigeria's military said Monday it had re-established control in five remote areas of the northeast where Islamist insurgents had seized territory, as it pressed on with a sweeping offensive against Boko Haram militants.

Several thousand troops were last week deployed across three states in the volatile region, and fighter jets have pounded Boko Haram camps as the military tries to rid the country of "terrorist activities."

The United States on Monday denounced what it called a spike in anti-Islamic sentiment in Europe and Asia, pointing to restrictions and violence against Muslims including the faith's minority sects.

Releasing a wide-ranging annual report on religious freedom, Secretary of State John Kerry also voiced alarm at what he called rising anti-Jewish sentiment, and filled a position of special envoy to combat anti-Semitism.

Russian security services said Monday they had foiled a terror attack on Moscow, killing two of the plotters and arresting another.

"Our forceful actions prevented an attempted act of terror in the capital," the National Anti-Terror Committee said in a statement.