Legal adviser to Burma’s National League for Democracy U Ko Ni was assassinated at Yangon International Airport on Sunday. “A very dark day for Myanmar. Just hearing the incredibly tragic and upsetting news that U Ko Ni was just assassinated at Yangon airport,” tweeted Thant Myint-U, the advisor to Myanmar president.

Ko Ni was shot dead when he was returning from a trip abroad, reported Frontier Myanmar, adding that the suspect has been arrested. The suspected shooter is a 53-year-old man from Mandalay, reported Myanmar Times. However, the police are yet to ascertain the motive of the killing. Pictures of a man in pink t-shirt covered in blood, identified as the suspect, are being shared widely on social media.

In November 2015, Aung San Suu Kyi’s NLD had won 80% of the Parliamentary seats, ending military rule in the country after nearly five decades. The NLD had bagged 348 seats across the lower and upper house of parliament, 19 more than the 329 needed for an absolute majority.