A joint operation by the navies of India and China thwarted an attack by suspected Somali pirates on a merchant ship in the Gulf of Aden, the Indian defence ministry said on Sunday (9 April).

The Tuvalu-flagged bulk carrier OS 35, was travelling from Kelang in Malaysia to the Yemeni port city of Aden on Saturday when it came under attack. It is reported to be the latest in a string of attacks after years of silence by Somali pirates.

A Chinese warship supported by an Indian navy helicopter rescued the merchant ship, which sent a distress call late on Saturday night.

Four of its navy ships responded to the signal and reached the bulk carrier early on Sunday, the Indian defence ministry said. They established contact with the captain of the merchant vessel who had taken refuge in the ship's strong room along with the rest of the crew, comprising of 19 Filipinos, in line with established safe shipping operating procedures, Reuters reported.

The Indian navy deployed a helicopter to provide air cover and sent two of its warships — INS Mumbai and INS Tarkash — in the direction of the bulk carrier. The two warships are thought to have been part of an Indian fleet of four vessels heading for an overseas deployment, the Hindustan Times reported.

"An Indian Navy helicopter undertook aerial reconnaissance of the merchant vessel at night, and at sunrise ... (to) ascertain the location of pirates, if still on board," the Indian defence ministry said in a statement. "Subsequently ... a boarding party from the nearby Chinese Navy ship went on board the merchant ship, while the Indian Naval helicopter provided air cover for the operation."

According to China's defence ministry, a Chinese navy frigate that was patrolling the area at the time of the incident responded to the distress signal from the ship that suggested it had been hijacked by pirates. Reuters reported that a helicopter shadowed the ship before deploying 16 navy special forces soldiers on board OS 35 to rescue the sailors.

Beijing, however, made no mention of the joint operation conducted with India in its statement, Reuters noted. But Indian media reported that China had thanked India for its cooperation.

Pakistani and Italian warships too reportedly responded to calls for help.

The coordinated operation comes amid strained ties between China and India over a range of issues, including border control, the Dalai Lama's visit to Tawang in the north eastern Indian state of Arunachal Pradesh and Beijing's opposition to Delhi's membership bid into the elite Nuclear Suppliers' Group.

The pirates are said to have fled the ship after Indian and Chinese navy warships moved in. UK Maritime Trade Operations, which coordinates shipping in the Gulf of Aden area, said the pirates used a skiff to approach the vessel.

Indian navy warship INS Mysore
Indian navy sent two of its warships in the direction of the bulk carrier upon receiving a distress call ~ representational image Indranil Mukherjee/AFP/Getty Images

The captain of the merchant vessel thanked the Indian navy for providing air cover. The ship has resumed sailing under navy escort to its next port, Reuters cited John Steed of aid group Oceans Beyond Piracy as saying.

The attempted hijack comes days after Somali pirates hijacked Sri-Lankan-flagged oil tanker Aris 13 in the Indian Ocean on 13 March, in what is thought to be the first hijack of a commercial ship by the pirates since 2012.