* Palestinian drives mechanical digger into Israeli bus
* Gunman wounds Israeli soldier in separate Jerusalem attack
* Tensions high in Jerusalem over Gaza war (Adds high alert in Tel Aviv)
By Jeffrey Heller
JERUSALEM, Aug 4 (Reuters) - A Palestinian killed an Israeli and overturned a bus with a construction vehicle on Monday and a gunman wounded a soldier in attacks in Jerusalem that appeared to be a backlash against Israel's Gaza war.
There were no passengers on the bus, in an ultra-Orthodox Jewish neighbourhood of the city. Surveillance video broadcast on Israeli television showed the yellow excavator's mechanical arm tearing into the side of the bus as it lay on the sidewalk.
Police identified the driver of the digger as a Palestinian from East Jerusalem and described the incident as a terrorist attack. Police officers shot him dead, and TV footage showed the man's body hanging out of the excavator's cabin.
Several hours later, a gunmen fired at a soldier, wounding him in the stomach, a few minutes' walk away. Police said the assailant then jumped on a waiting motorcycle and sped away.
"We very much suspect that this was a terrorist attack," said Yossi Parienti, Jerusalem district police chief, told Channel Two television.
A high alert was also called in Israel's commercial hub, Tel Aviv. Police set up road blocks in the city, causing widespread congestion, although they were later removed.
Tensions have been high in Jerusalem for the past month over the Gaza war and the killing of a Palestinian teen in the city by alleged Israeli assailants out to avenge the deaths of three abducted Israeli youngsters in the occupied West Bank.
There were no immediate claims of responsibility for Monday's attacks in Jerusalem.
But a spokesman for Hamas, the dominant group in the Gaza Strip, said: "We praise the heroic and brave operations in Jerusalem, which come as a natural reaction to the crimes and massacres by the Occupation against our people in Gaza."
Describing the excavator incident, Parienti said the vehicle "hit a Jewish citizen at a construction site and then drove about 50 metres (yards) down the road, where it overturned the bus with its arm, slightly injuring three people".
Internal Security Minister Yitzhak Aharonovitch said the nearly four-week-old Gaza war had raised fears of attacks in Israeli cities.
"From the moment fighting started in the south, we realised such an incident of a lone attacker can happen, and such tractor attacks are familiar in Jerusalem," Aharonovitch said on Channel 2 television.
"(The driver's) whole family is being interrogated. We want to know who sent him, if he was acting alone, whether he belonged to a network - all those things are being checked," he said.
In two incidents in July 2008, construction vehicles driven by Palestinians hit Israeli buses and pedestrians, killing a total of three people. In both incidents, the attackers were shot dead.
Three years later, an Arab truck driver drove into cars and pedestrians in Tel Aviv, killing one person, in what police said was a deliberate attack. The driver was apprehended and sentenced to life imprisonment. (Additional reporting by Maayan Lubell and Ori Lewis in Jerusalem and Nidal al-Mughrabi in Gaza; Editing by Giles Elgood, Larry King)