New Delhi, March 13: The Indian Ocean is becoming the focal point in the hunt for Malaysia Airlines Flight MH 370, drawing an armada of warships and military aircraft to the region.

Looking for a little black box in the big blue, India today sent warships and surveillance aircraft to the Andaman Sea on a request from Kuala Lumpur.

An American destroyer, the Kidd, was redeploying to the Strait of Malacca west of Malaysia, the Seventh Fleet and Pentagon officials said — one of several indications that the hunt was turning away from the eastern waters and towards the vastness of the Indian Ocean in the west.

Malaysian officials said they had expanded the search into the Andaman Sea, the part of the Indian Ocean northwest of the strait. The Pentagon said that the Kidd would be searching there, at the request of the Malaysian government, and that a P-3 surveillance plane had already flown over the area.

Yet, in a measure of the continued caution and bafflement among the authorities in Malaysia, defence minister said the main search effort continued to be east of the Malaysian peninsula, in the Gulf of Thailand and the South China Sea.

Pentagon officials said that several American agencies were reviewing radar signals, but had not yet found anything that would indicate specifically where the plane might have gone down. The White House said a search area might be opened in the Indian Ocean.

Four Indian ships, two of them with onboard helicopters, and three fixed-wing aircraft have been deployed by the Indian Navy and the Indian Coast Guard from the Andaman and Nicobar command and from Arakonnam in Tamil Nadu.

The Indian Air Force has deployed two C-130J aircraft, part of a squadron known as the “Veiled Vipers”.

The Indian Navy has been designated the lead agency for the Indian search and rescue operation tentatively named “Searchlight”.

Its Maritime Operations Centre (MOC) in New Delhi is in “realtime contact” with the Royal Malaysian Navy headquarters, navy sources said.

The Royal Malaysian Navy will tell the Indian Navy where to concentrate its forces in a zone that is about 17,000 nautical square miles.

The zone will be broken up into a grid and navies and air forces from other countries that are heading for the Andaman Sea from the east will be similarly tasked.

The western extremity of the area is about 60 nautical miles east of Campbell Bay in the Nicobar islands where the Indian Navy has an airbase named INS Baaz headed by Commander Naresh Sharma. The Baaz, which has a runway, is a strategic listening and watching post for the Strait of Malacca opened only in 2012.

The deputy chief of naval staff, Vice-Adm. P.K. Chatterjee is heading the operation with the Director General of Naval Operations, Vice Admiral Girish Luthra, and the chief of the joint services Andaman and Nicobar Command, Air Marshal P K Roy providing the forces. There are 15 ships in the command.

Four ships designated for patrolling the area that have sailed out from Port Blair and Campbell Bay are amphibious warfare ships : the INS Kesari headed by Commander Mahesh Mangipudi is an LSTL (Landing Ship Tank-Large) and the INS Kumbhir under Commander Caesar Basu is an LST (medium).

An offshore patrol vessel, the INS Saryu, and a fast patrol craft, Indian Coast Guard Ship Kanaklata Barua, are expected to be among the first of the ships to reach the zone. A Dornier each from the Coast Guard and the Navy made first sorties from Port Blair this afternoon.

From INS Rajali at Arakonnam in Tamil Nadu, a P81 Poseidon long-range maritime patrol aircraft from squadron commander Captain Harjit Singh Jhajj’s unit flew out. It will be based in Port Blair.

The searchers will have to primarily depend on visual sighting of the MH370, or parts of it. But the P81 aircraft with two-dimension radar on board may also be able to capture pictures of flotsam. Spotting flotsam is difficult by radar signatures because waves in the sea may deflect radio waves.

Typically, from an aircraft flying at about 1500 feet, the field of vision with binoculars will cover about eight nautical miles.

Information emerged that communications satellites picked up faint electronic pulses from Flight 370 after it was reported missing on Saturday, but the signals gave no information about where the stray jet was heading and little else about its fate.

The “pings” indicated that the aircraft’s maintenance troubleshooting systems were switched on and ready to communicate with satellites as needed. But no data links were opened because the companies involved had not subscribed to that level of service from the satellite operator, sources said.

The system transmits such pings about once an hour, the sources said, but it remains unclear how many signals the plane sent after air traffic control lost track of it.

Boeing Co, which made the missing 777 airliner, and Rolls-Royce, which supplied its Trent engines, declined to comment.

Earlier, Malaysian officials denied reports that the aircraft had continued to send technical data and said there was no evidence that it flew for hours after losing contact with air traffic controllers early on Saturday after taking off from Kuala Lumpur en route to Beijing.

The Wall Street Journal had reported that US aviation investigators and national security officials believed the Boeing 777 flew for a total of five hours, based on data automatically downloaded and sent to the ground from its engines as part of a standard monitoring program.

Sources familiar with the investigation iterated that neither Boeing nor Rolls-Royce had received any engine maintenance data from the jet after the point at which its pilots last made contact.