MANILA (Reuters) - The Philippine military on Tuesday rejected Chinese allegations that troops stationed on a warship grounded on a disputed South China Sea shoal had pointed guns at its coast guard, insisting its personnel maintained professional conduct.

Philippine troops are governed by rules of engagement and acted with the highest level of professionalism, military spokesperson Francel Margareth Padilla told a press conference.

Chinese state media said on Sunday personnel on a Philippine ship pointed guns at China's coast guard last month at the Second Thomas Shoal, a flashpoint for repeated flare-ups between the two countries.

Philippine military chief Romeo Brawner said the grounded warship is a commissioned vessel of the Philippine navy so it is authorised to have weapons.

"We have the right to defend ourselves," Brawner said, adding the Philippines will continue to assert its sovereignty in the area.

The Second Thomas Shoal is located inside the Philippines' exclusive economic zone and China has for years challenged the country's deployment of a small contingent of marines there aboard a rusty former U.S. ship.

The Sierra Madre was intentionally grounded on the shoal by the Philippines in 1999, as a means of asserting what it says is its sovereignty over the area. China has been accused by Manila of repeated aggressive conduct in disrupting resupply missions to the troops.

China claims almost the entire South China Sea as its territory, deploying an armada of coast guard vessels, some more than 1,000 km away from its mainland. China has maintained its responses have been appropriate in the face of Philippine encroachment.

(Reporting by Karen Lema; Writing by Neil Jerome Morales; Editing by John Mair, Martin Petty)

By Karen Lema