MUMBAI • India's navy was put on high alert yesterday in the city of Mumbai, an official said, after witnesses saw several men dressed in black carrying weapons near a naval base, Agence France-Presse reported.

Security was strengthened at several naval facilities along the coast in and around India's financial capital, while officials investigated the reports.

"The navy is in a high state of alert in Mumbai and adjoining areas after receiving inputs regarding suspicious activity reported by school children," navy spokesman Captain DK Sharma told AFP.

Captain Sharma did not reveal the nature of the activity, but local media reported that the children had seen gunmen, their faces covered, near a naval facility at Uran, located about 50km from Mumbai.

There were conflicting reports about the number of gunmen sighted, with some saying there were between four and six. The men were reportedly also carrying backpacks and speaking in a foreign language.

Indian media reports said police searched an area around Uran to hunt for the gunmen, while India's counter-terrorism forces and the navy combed the Mumbai coast and all sea routes leading to Indian ports.

"We are taking utmost care and precautions," Mumbai police spokesman Ashok Dudhe told AFP.

The police issued an alert to fishermen asking them to be vigilant and to report any suspicious persons or activities around the Mumbai coast. Schools in and around Uran were also ordered to close, CNN News 18 reported.

Mumbai is particularly sensitive to security threats after gunmen, who arrived by sea, went on a three-day rampage in 2008 in the western city that left 166 people dead. India blamed the attacks on Pakistani militants.

In January, an Indian air force base in Pathankot in the northern state of Punjab came under attack by the Pakistan-based militant group Jaish-e-Mohammad. Seven Indian security personnel were killed.

India had already been on guard since Sunday, when militants raided an army base near the de facto border that divides the northern Kashmir region with Pakistan, killing 18 soldiers. India said the Jaish-e-Mohammad group was responsible for that attack.