A pair of Palestinian men boarded a bus in Jerusalem and began shooting and stabbing passengers, officials in Israel said.
In a near simultaneous attack, another assailant rammed a car into a bus station before stabbing bystanders. The two incidents left three Israelis and one attacker dead.
The Jerusalem attacks, along with two stabbings in a central Israeli city, marked the most serious outbreak of violence since the current round of tensions erupted. More than 15 people were wounded.
The violence, coming at a time when peace prospects appear low, have fuelled a sense of panic in Israel and raised fears that the region is on the cusp of a new round of heavy violence.
Police closed major highways leading in and out of Jerusalem, while Prime Minister Benjamin Netanyahu called an emergency meeting of his Security Cabinet, where police were to present a plan to halt the violence.
Police spokeswoman Luba Samri said the country’s internal security minister, Gilad Erdan, was considering a number of immediate steps, including sealing off Arab neighbourhoods in east Jerusalem, where many of the attackers have come from, and making it easier to get gun licences.
While Israelis are on edge over the random nature of the attacks, the long-running diplomatic deadlock has left many Palestinians feeling hopeless about their chances of ending nearly half a century of Israeli occupation.
In the bus attack, police said two men – one carrying a gun and the other with a knife, boarded the vehicle and attacked passengers.
Police said a 60-year-old man was killed, and a second person who was wounded later died. One of the attackers was shot dead and the second attacker was subdued by a crowd.
Elsewhere in Jerusalem, a Palestinian motorist rammed his vehicle into a crowded bus stop, then got out and began stabbing people. One Israeli was killed, police said.
The Jerusalem attacks, coupled with a pair of stabbing attacks in the central Israeli city of Raanana that injured five – including one seriously, came in rapid succession. Emergency services said several of the wounded were in serious condition.
At the scene of one of the attacks, Jerusalem Mayor Nir Barkat called on the government to seal off the West Bank and certain Arab neighbourhoods of east Jerusalem to quell the wave of attacks that have struck the city. Some government ministers have called for even more dramatic measures.
Since the Jewish New Year last month, eight Israelis have been killed and dozens wounded in a series of attacks.
At least 27 Palestinians been killed by Israeli fire, including 11 identified by Israel as attackers and the rest in clashes between stone-throwers and Israeli troops. Hundreds of Palestinians have been wounded in such confrontations.