Israeli Prime Minister Benjamin Netanyahu instructed the military to carry out an "intensive" operation in the West Bank after explosions on buses close to Tel Aviv on Thursday, in what Netanyahu's office described as an attempted mass attack.
No casualties were reported.
The Israeli police earlier said there had been explosions on three buses in two Israeli suburbs outside Tel Aviv and that four explosive devices had been found. Local media reported the explosions had occurred on buses in depots and were empty.
The explosions were a stark reminder of the devastating bus bombings in Israel that were a hallmark of the Palestinian uprising of the 2000s, although such attacks are now rare.
The military said in a statement that it was assisting the police and Shin Bet intelligence agency in the investigation. The police said it was searching for suspects, advising the public to remain vigilant.
There was no immediate claim of responsibility for the explosions. Netanyahu met with the defense minister, head of the military and Shin Bet and the police commissioner following the explosions, his office said. A police spokesperson said that improvised explosive devices with timers had been identified and public transportation had been searched for any further devices.
A video published by local media showed what appeared to be a bus on fire at a depot and a photo of a burned out bus.
The military said it would intensify counter-terrorism operations in the West Bank and that it had blocked entry points in certain areas, without specifying where. The military has been conducting a large scale military operation in the West Bank over the past month that it says is targeting rebel groups.
Tens of thousands of Palestinians have been forced to leave their homes in West Bank refugee camps, while homes and infrastructure have been demolished.
The bus blasts come amid a fragile ceasefire in Gaza between Hamas and Israel after 16 months of war. Hamas on Thursday released the bodies of four hostages.
The ceasefire has held since it was implemented on January 19 despite accusations traded by Israel and Hamas of violations.

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