The Western Naval Command issued a high alert along the Mumbai coast after men in military uniform were allegedly spotted near a Naval facility in Uran, about 47 kms from Mumbai, on 22 September.
A search is on to trace the men, police said. According to Indian Navy Chief PRO Capt D K Sharma, a search operation is underway.
The Western Naval Command (WNC) issued "the highest state of alert" along the Mumbai, Navi Mumbai, Thane and Raigad coasts after suspicious movement of a group was reported in Uran.
The WNC has roped-in the police and the Coast Guard for the task.
According to initial information received by the authorities, four school students spotted a group of people dressed in uniform similar to that of Indian Army near Uran and Karanja area.
The DGP office immediately issued alerts to all police stations along the coast.
Security has been beefed up at sensitive locations along the coast, including the Gateway of India, Raj Bhawan, Bombay High (rig), Bhabha Atomic Research Centre and other major establishments near the sea.