Putrajaya has been told to take action against Chinese Coast Guard (CCG) vessels that have been constantly patrolling waters claimed by Malaysia, as the move allegedly violates Malaysian sovereignty.

In a statement today, PKR Youth chief Nik Nazmi Nik Ahmad said Putrajaya should take firmer action to protest the presence of Chinese vessels.

"This is obviously a challenge to the country's sovereignty," he said.

According to a recent report which tracked ship movements near the Luconia Shoals over a 60-day period, three Chinese vessels have been patrolling the shoal from Dec 30, 2016 onwards.

The report was a collaboration between the Centre for Strategic and International Studies’ (CSIS) Asia Maritime Transparency Initiative, and the Centre for Advanced Defense Studies (C4ADS). Both are US-based think-tanks.

The report said the CCG ship movements are not unusual, and are consistent with a regular rotation of CCG ships near the Luconia Shoals, which CSIS and C4ADS have traced back to January 2016.

The shoals are some 156 kilometres off the coast of Sarawak, and have been claimed by Malaysia as part of its exclusive economic zone. It comprises two groups of reefs, known as the North Luconia Shoals (Gugusan Beting Raja Jarun) and South Luconia Shoals (Gugusan Beting Patinggi Ali).

In 2015, Malaysia lodged a diplomatic protest against China after a CCG vessel was reportedly moored off the Luconia Shoals for two years.

"Since that time, at least 11 CCG vessels have patrolled the shoals," the report said.

Nik Nazmi asked if the government would continue to remain silent and agree to China's intrusion into Malaysian waters.

"It's not just about their presence in our waters. Given Prime Minister Najib Abdul Razak’s weak administration, and major scandals such as 1MDB, it is as though we are giving an opportunity to foreign countries, such as China, to infiltrate the country's politics and economy," he said.

"If Putrajaya still fails to come up with a firmer stance on the matter, then it is clear that Najib's administration is unable to uphold the country's sovereignty. This would continue to open (us) up to foreign interference," he said.