BBC在线收听下载:蓝鲸的的叫声受季节性噪音影响

Hello, I'm Neil Nunes with the BBC News.

Three Philippine policemen enforcing President Duterte's war on drugs have been found guilty of an extrajudicial killing. They each face prison sentences of up to forty years for the murder of a seventeen-year-old boy. The BBC's Howard Johnson reports now from Manila.

The killing of Kian Delos Santos sparked protests in the Philippines after CCTV footage and eyewitness accounts contradicted the official police report into his death. Police officers claim they shot the high school student after open fire on them during an anti-drug operation. But video footage showed the teenager being dragged towards the area where he was killed. One eyewitness said he begged for his life before being shot by the police. President Rodrigo Duterte has been criticized in the path for promising to pardon police officers convicted of drug war killings.

South Korea's highest court has ruled that a second Japanese company must pay compensation to Koreans employed as forced labor during the Second World War. The Japanese Foreign Minister Taro Kono called Thursday's ruling unacceptable. Laura Bicker in Seoul has more.

Mitsubishi Heavy Industries Ltd has been ordered to pay 80 million yen or around 71,000 dollars each to 23 South Koreans seeking compensation for forced labor. They are just a few of the 150,000 Koreans who were conscripted to work in factories and mines in Japan during World War II. Last month, in a landmark ruling, the Supreme Court in Seoul ordered Nippon Steel and Sumitomo Metal to compensate four Koreans for their forced labor, which prompted outrage from the Japanese government.

Scientists investigating variations on the calls made by blue whales have found that the biggest marine mammals are affected by seasonal ambient noise. Here's Kate Rena.

The sound of a blue whale can travel over a thousand kilometers and is one of the loudest sounds in the ocean. In part of a wide-ranging study conducted in the Southern Indian Ocean, researchers found that these calls became higher pitch in the summer, possibly in order to be heard over the crash of breaking sea ice. As well as seasonal variations, it's been observed that the frequency of whale song has been dropping over the last few decades. The scientists suggest that as population density rises as a result of whaling restrictions, the vast creatures' song no longer needs to carry as far.

BBC News.