evidence: BEIJING - Three Chinese ships on Sunday patrolled the James Shoal, an area also claimed by Malaysia, and soldiers and officers on board swore to safeguard its sovereignty, in the latest sign of Beijing's territorial assertiveness in the South China Sea. [...] Beijing regards the James Shoal as the southernmost part of the country's territory. Last March, Malaysia protested against the incursion of four Chinese ships in James Shoal, about 80 km (50 miles) off Sarawak on Borneo island. Chinese sailors fired guns in the air during the visit to the shoal. In April, a Chinese maritime surveillance ship returned to James Shoal to leave behind steel markers to assert its claim.