Six suspected drug dealers were shot dead during a firefight with Thai security forces who seized illegal amphetamines at the scene, police said Saturday.

The clash occurred late Friday evening in a mountainous border area in the Mae Sai district of northernmost Chiang Rai province -- part of the Golden Triangle region.

A magnetic bomb attached to a district governor's vehicle exploded in eastern Afghanistan on Saturday, killing the governor and his bodyguard, provincial authorities said.

The attack in Nangarhar province highlights the security threat surrounding presidential elections in a month's time, when voters will choose a successor to Hamid Karzai.

Sri Lankan authorities halted excavations after recovering 81 skeletal remains from an unmarked mass grave atop an old burial ground in the island's former war zone, an official said Saturday.

Judicial medical officer Dhananjaya Waidyaratne said digging at a depth of about two meters (6.7 feet) led to the old cemetery and the authorities did not want to go deeper and disturbed those who had been properly buried.

China's foreign minister on Saturday said his country will vigorously defend its sovereignty, declaring there was "no room for compromise" with Japan over territory or history.

"We will never bully smaller countries yet we will never accept unreasonable demands from smaller countries," Wang Yi, the minister of foreign affairs, told reporters.

Venezuelans will march again on Saturday against the country's chronic food shortage, one of the major grievances in a wave of protests shadowing President Nicolas Maduro's government.

At least 20 people have now died in Venezuela since protests first erupted a month ago, giving Maduro his biggest test since succeeding late leader Hugo Chavez almost a year ago.

Senator Rand Paul, a potential Republican White House contender in 2016, electrified conservative activists Friday by warning that President Barack Obama was taking America down the road to tyranny.

"Imagine a time when the White House is once again occupied by a friend of liberty," the libertarian-leaning lawmaker told the Conservative Public Action Committee (CPAC), where he is hugely popular with small-government Tea Party Republicans.

U.S. border authorities unveiled a new set of guidelines Friday in an effort to drastically reduce instances of agents shooting at moving vehicles or at migrants throwing rocks, reversing a policy that left several dead.

Border Patrol Chief Michael Fisher ordered customs and border agents not to shoot at vehicles when their occupants are fleeing and also barred officials from placing themselves in the path of a vehicle or using their body to block its path.

The governments of the United States, Mexico and Guatemala formed a special body Friday to fight drug trafficking and organized crime.

The Trilateral Security Desk evaluates intelligence and border risks to combat human trafficking and the smuggling of illegal weapons and drugs in the region, Guatemalan Interior Minister Mauricio Lopez told reporters.

Russian President Vladimir Putin has seemingly been in the "deep freeze" since the Cold War and is applying its outdated KGB mentality in Ukraine, Britain's deputy prime minister said Saturday.

Speaking to The Guardian newspaper, Nick Clegg said Putin was applying "yesterday's divisions and arguments to today's problems".

Ukraine braced Saturday for new pro-Russian protests in the tense eastern city of Donetsk after Moscow threatened to stop crucial gas supplies to the country, further escalating hostilities with the West.

Donetsk, a focal point of the crisis engulfing Ukraine since the protests that toppled president Viktor Yanukovych, was expecting a large demonstration by activists demanding a secession referendum like the one planned for the Crimean peninsula.