The military and Israeli police have not found any firm evidence that Palestinian rockets have landed close to Israel's commercial and business capital, but say such weapons may have landed in the sea nearby.
Air raid sirens have been sounded after explosions were heard in the last two days.
"A fifth Iron Dome batteries have been redeployed in the vicinity of the city. The other four are in the southern districts," a military source told RIA Novosti.
Rocket strikes have previously only threatened southern Israel in the last decade, where only a million people, or one-eighth of the population lives.
However, Palestinian militants claim to have fired rockets twice in the last two days close to Tel Aviv, which has not come under attack since the Gulf War in 1991 when Iraq fired on Israel with Scud missiles.
Another rocket fell Thursday close to Rishon Lezion, also in the central part of Israel. Remnants of a rocket were also found Friday near Jerusalem, which both Israelis and Palestinians consider their capital.
Neither rocket did any damage. The Israel army says 3.5 million of its citizens live within range of the fallen rockets.
The Iron Dome system is optimised for defence against short- and medium-range rocket systems like the Kassam, Grad and Fadzhr rockets mainly used by Lebanese and Palestinian militant groups in attacks on Israel.
Iron Dome has intercepted at least 200 incoming rockets since the latest fighting broke out Wednesday, while around another 400 have landed in Israel, the army says.
Iron Dome is an expensive system, costing thousands of dollars a shot, as against the hundreds required for the Palestinian's Kassam, but its makers claim it can assess the trajectory of those rockets which present a real threat and ignore those which are not heading toward objects requiring protection.
The fifth Iron Dome was due to enter service in 2013, but was rushed into service from trials two months early to take part in the current operation, an IDF source told RIA Novosti.
Tel Aviv: Israel has redeployed its Iron Dome air-defence systems to protect Tel Aviv from Palestinian rocket fire.
First Published: Sunday, November 18, 2012, 08:38