Kenyan police have arrested more than 650 suspects a day after six people were killed in bomb attacks in the capital Nairobi, the interior minister said Tuesday, in a crackdown on suspected Islamist insurgents.

"This act of cowardice perpetrated against innocent and peace-loving Kenyans who were going about their normal activities is barbaric," Interior Minister Joseph Ole Lenku said in a statement.

The U.N.'s refugee agency said Tuesday it was prepared to help evacuate some 19,000 Muslims at risk of attack from mainly Christian militias in the conflict-torn Central African Republic.

"What we don't want is to stand by and watch people being slaughtered," UNHCR spokeswoman Fatoumata Lejeune-Kaba told reporters in Geneva.

Afghan police seized 22 tonnes of explosives destined for use in suicide and roadside bombs, officials said Tuesday, four days before elections that Taliban insurgents have vowed to attack.

The explosives were uncovered in dozens of plastic-wrapped bags in the northern province of Takhar, as security forces ramp up efforts to protect candidates, election staff and voters.

Malaysia revealed the full radio communications with the pilots of its missing flight Tuesday, but the routine exchanges shed no light on the mystery as an Indian Ocean search for wreckage bore on with no end in sight.

The previously unreleased conversations between MH370's pilots and air traffic controllers had been the subject of much speculation as suspicions have focused on whether one or both of its pilots deliberately diverted the plane on March 8 with 239 people aboard.

A Thai anti-government protester was shot dead and several others wounded Tuesday when their convoy was attacked on a busy expressway, officials said, reigniting tensions in Bangkok after weeks of relative calm.

The victims, supporters of a militant faction of the opposition movement, were returning from a rally at a government complex in the north of the capital when they were fired on by unknown assailants.

Turkey's secular opposition on Tuesday rejected the results of Ankara and Istanbul mayoral elections claimed as victories by the Islamic-rooted party of Premier Recep Tayyip Erdogan, citing "irregularities".

More than 1,000 people demonstrated outside the elections authority in the capital Ankara, where the incumbent mayor of Erdogan's ruling party has declared victory with a wafer-thin margin of about one percent.

Ukraine's parliament on Tuesday approved a series of joint military exercises with NATO countries that would put U.S. troops in direct proximity to Russian forces in the annexed Crimea peninsula.

"This is a good opportunity to develop our armed forces," acting defense minister Mykhailo Koval told Verkhovna Rada lawmakers ahead of the 235-0 vote.

Three fishermen were killed and two were missing after a giant cargo ship crashed into their trawler off northern Spain on Tuesday, officials said.

The Baltic Breeze, a 164-meter (541-foot) vehicle-carrier, collided with the 34-meter Mar de Marin near the Spanish port of Vigo, the local coastguard said.

South Korea on Tuesday urged North Korea to stop making "senseless" personal attacks on President Park Geun-Hye following a series of increasingly vitriolic diatribes published by Pyongyang's state media.

A government statement called on the North to "act discreetly" in line with a recent cross-border agreement for the two countries to stop slandering one another.

Tibetans in Nepal face heightened risks of being detained, beaten and even forcibly returned to China, as Kathmandu bows to growing diplomatic pressure from Beijing, Human Rights Watch said Tuesday.

The allegations, detailed in a new report based on the testimony of Tibetan refugees, monks, activists and senior Nepalese officials, highlight the intensified restrictions slapped on Tibetans in the Himalayan nation since 2008.