Sri Lanka's police arrested 35 suspected Tamil asylum seekers off the coast near Weligama, in the south of the country, Xinhua reported.

The Tamils, aged between 30 and 40, are all resident in the Northern Province towns of Jaffna, Mankulam, Chavakacheri, Olumadu, Vavuniya, Mullaitivu, Oddusuddan and Mallavi.

According to Xinhua, the arrests on Wednesday were the first of Tamils attempting to flee the country since the new government of Maithripala Sirisena came into power in January.

Police said the Tamils were preparing to sail to another country when they were spotted by the navy.

The US said it welcomes the nuclear agreement signed between India and Sri Lanka during President Maithripala Sirisena's visit to Delhi earlier this week.

State Department spokesperson Jen Psaki told a press briefing on Tuesday the US was aware of the announcement and welcomed regional cooperation.

"We welcome regional cooperation on nuclear energy that is consistent with IAEA safeguards and other international standards and practices," she said.

The deal will see India assist Sri Lanka to build its nuclear energy infrastructure, the Indian foreign ministry said on Monday.

The TNA's MA Sumanthiran called for a strong report on the OHCHR Investigation on Sri Lanka (OISL), on its delayed release in September.

Speaking to media on Tuesday, the MP said the deferral of the report caused disappointment to the victims, but that UN officials had expressed their confidence that the delayed report will be stronger than if it was released in March.

Mr Sumanthiran said it was important the report is "solid and strong and should liberate our people from their worries".

The Chinese government welcomed the growing partnership between India and Sri Lanka and expressed hope that it can develop its own relationships with both countries.

Foreign Ministry spokesperson Hua Chunying told media on Tuesday, both Sri Lanka and India are "important and friendly neighbours of China," and good relationships between the three countries will benefit regional stability.

"We hope to work with India to further develop the strategic cooperative partnership for peace and prosperity. We also look forward to fostering the strategic cooperative partnership featuring sincere mutual assistance and long-lasting friendship with the Sri Lankan side," she said.