Chinese navy ship supported by an Indian navy helicopter thwarted an attack on a Tuvalu-flagged merchant ship by suspected Somali pirates, India's defense ministry said on Sunday.

The OS 35 was reported to be under attack on Saturday.

"An Indian Navy helicopter undertook aerial reconnaissance of the merchant vessel at night, and at sunrise, to sanitize the upper decks of the merchant ship and ascertain the location of pirates, if still on board," the defense 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."