BEIJING: China's coast guard said on Sunday it "lawfully" blocked Philippine vessels transporting "illegal construction materials" to a warship at a disputed shoal in the South China Sea. Over the past few months, China and the Philippines have had numerous run-ins in areas of the South China Sea, most notable the disputed Second Thomas Shoal, part of the Spratly Islands. The Philippines has been sending supplies to troops stationed on a World War Two-era, transport-ship-turned-military outpost on the shoal, prompting the China Coast Guard to repeatedly deploy vessels to block the resupply missions. Last week, the Philippine military demanded China stop its "dangerous and offensive" actions, after a Chinese navy ship shadowed and attempted to cut off a Philippine navy vessel conducting a resupply mission.