Washington stresses it stands by Manila after a laser was directed at the Philippine Coast Guard near the Second Thomas Shoal.

The incident happened as the Philippine Coast Guard (PCG) was on a mission to resupply troops at Second Thomas Shoal, known as Ayungin Shoal in the Philippines, on February 6.

The coast guard said the boat was targeted with a “military-grade laser” that temporarily blinded the crew, and accused the Chinese vessel of engaging in “dangerous” manoeuvres.

“The United States stands with our Philippine allies in the face of the People’s Republic of China (PRC) Coast Guard’s reported use of laser devices against the crew of a Philippine Coast Guard ship,” US State Department spokesperson Ned Price said in a statement.

“The PRC’s conduct was provocative and unsafe.”

Second Thomas Shoal lies about 105 nautical miles (195km) northwest of the Philippine province of Palawan in the disputed Spratly Islands.

Within the Philippines’s Exclusive Economic Zone (EEZ), the shoal is home to a small group of Philippine soldiers living on board a rusting World War II-era ship known as the Sierra Madre, which was deliberately grounded there in 1999 to underline the country’s claim of sovereignty.

In his statement, Price referred to a July 2016 international court ruling that found there was no legal basis for China’s claim to almost the entire South China Sea. The action was brought by the Philippines, but Beijing has refused to recognise the decision.

“The United States reiterates, pursuant to the 1982 Law of the Sea Convention, the 2016 arbitral decision is final and legally binding on the PRC and the Philippines, and we call upon the PRC to abide by the ruling,” Price said in the statement.

After the PCG revealed the encounter on Monday, the Philippine military urged Beijing to control its forces in the disputed sea, which is also claimed by Taiwan and a number of Southeast Asian countries.

“I think it’s time for the Chinese government to restrain its forces so that it does not commit any provocative act that will endanger the lives of people,” military spokesperson Medel Aguilar told reporters on Monday.

Aguilar quoted the Philippine defence chief as saying the Chinese action was “offensive” and unsafe.

The incident took place when the PCG vessel was about 10 nautical miles (18.5km) from Second Thomas Shoal, according to the Philippines. China also blocked access to the shoal last August, it added, with two Chinese coast guard vessels joining two ships from China’s maritime militia to create a “blockade”.

China’s foreign ministry maintains that its coast guard acts in accordance with the law.

“We urge the Philippines to avoid such actions, and the actions of China’s staff are professional and restrained,” China’s foreign ministry spokesperson, Wang Wenbin, told a regular briefing on Monday.

China has become increasingly assertive over its claim to the South China Sea, developing military bases on rocky outcrops and deploying the coastguard, its maritime militia and fishing vessels in support of its claims.

The PCG reiterated that it will continue to support and protect the “sovereignty and rights” of the Philippines and the troops on board the Sierra Madre.

The Philippines recently agreed to allow the United States access to more of its military bases under the Enhanced Defense Cooperation Agreement (EDCA) between the two countries.

Last week, it also announced it would boost security ties with Japan.