SINGAPORE/NEW DELHI - An Indian submarine and two Chinese warships on an anti-piracy mission were recently locked in a tense standoff in the waters off Somalia, Chinese media reports said Wednesday. The Indian Navy said none of its submarines were in the area.

In a rare reporting of the incident, Qingdao Chenbao, a Chinese daily, said the Indian submarine ’stalked’ the Chinese warships and they were ‘locked in a tense standoff for at least half an hour’ after which the Indian submarine was forced to surface.

The submarine and the two warships were involved in several rounds of manoeuvring during which both sides evidently tried to test each other’s sonar systems for weaknesses. The incident occurred Jan 15 in the waters near the Bab Al-Mandab Strait.

An Indian Navy spokesperson told IANS in New Delhi that ‘no Indian submarine surfaced in the area’.

The Chinese report, which first appeared Tuesday, had been picked up by numerous mainland Chinese websites a day later. Chinese warships have been patrolling in the waters off the Gulf of Aden, one of the world’s busiest sea routes, to prevent piracy attacks.

China has not officially commented on the incident, which reportedly ended when the Indian vessel left without further confrontation.

The Chinese ships had picked up sonar signals of an unidentified submarine, which the Chinese navy identified as a submarine armed with around 20 torpedoes belonging to the Indian navy, the South China Morning Post said in its report on the incident.

The submarine moved into deeper waters but was tracked by an anti-submarine helicopter, cornered and forced to surface. The submarine had been trailing the Chinese ships since they entered the Indian Ocean on its way to the Gulf of Aden, the paper said.

The waters around the Gulf of Aden have turned extremely hazardous for commercial shipping following attacks by Somalia-based pirates. India is among several countries, including the US, Britain, France, Iran, South Korea and China, that have sent warships to patrol the sea lanes in the area to prevent attacks by pirates.