Sri Lanka has allowed a Chinese submarine and a warship to dock at its port in Colombo, officials said on Sunday, despite concerns raised by India about China's warming relations with the Indian Ocean island nation.

Submarine Changzheng-2 and warship Chang Xing Dao arrived at the port on Friday, seven weeks after another Chinese submarine, a long-range deployment patrol, had called at the same port ahead of a visit to South Asia by Chinese President Xi Jinping.

"A submarine and a warship have docked at Colombo harbor. They called on Oct. 31 and will be here for five days for refueling and crew refreshment," Sri Lankan navy spokesman Kosala Warnakulasuriya said.