Explosions tore through three empty buses in parking lots in the Tel Aviv suburbs of Bat Yam and Holon on Thursday evening, several Israeli media outlets reported.
No one was injured, and the incidents are being investigated, the Yedioth Ahronoth daily reported, citing police.
A police statement said a large number of officers has been deployed to the explosion sites, conducting searches for suspects, while bomb disposal experts are examining the scenes to ensure that no additional explosive devices or suspicious objects are present.
The police also released photos from the scenes but did not provide further details regarding the nature of the blasts.
Israel's public broadcaster KAN reported that the Shin Bet internal security agency and the police are assessing whether the incident was a coordinated attack.
According to Yedioth Ahronoth, all light rail lines in Bat Yam were halted Thursday evening following the explosions.
Bus drivers across Israel were also ordered to stop and search their vehicles for any suspicious objects, the daily added.
Police also found two unexploded devices attached to buses in Holon and Bat Yam, it said.
Israeli Army Radio later reported that one of the devices found in Bat Yam had "revenge for Tulkarem camp" written on it.
Israel's Channel 12 later reported that Defense Minister Israel Katz has instructed the Israeli army to intensify military operations in the West Bank in response to the blasts.
Meanwhile, Channel 13 quoted an unnamed official from Prime Minister Benjamin Netanyahu's office as saying that Netanyahu views the planting of the explosive devices on buses as highly serious and will order strict measures against armed groups in the West Bank.
The office further announced that he plans to convene a security meeting soon to evaluate the situation.
