The Philippines expressed “serious concerns” over the presence of China’s strategic bombers in the disputed South China Sea and its foreign ministry has taken “appropriate diplomatic action”, the spokesman of President Rodrigo Duterte said on Monday. Meanwhile, Vietnam’s foreign ministry spokesperson, Le Thi Thu Hang, said the flights of Chinese aircrafts “increase tensions, cause regional instabilities and are not good for maintaining a peaceful, stable and cooperative environment in the East Sea.” Beijing appeared to up the ante in the South China Sea on Friday by releasing footage of its H-6K nuclear-capable bombers landing on artificially made islands in disputed waters – and it sends a clear message that it dominates the region.