A Palestinian bomber blew himself up at a cafe in Jerusalem Tuesday night, killing at least four other people and wounding about 40 others, rescue workers and witnesses said. The bomber struck at the popular Cafe Hillel on a strip with many restaurants and small shops. Ambulances rushed to the residential neighborhood, and workers carried away the wounded on stretchers. Four bodies were seen at the site of the blast, Israel Army radio reported. It was unclear if one of them was the bomber, who police said managed to get into the cafe even though two security guards were posted at the entrance - one inside the door and one outside. Jerusalem police commander Mickey Levy told Israel Radio that one of the guards saw the bomber and tried to stop him, and that he then set off the bomb. Also, eight people, including the suspected bomber, have been killed and tens more injured in an explosion at a bus stop outside an army base near Tel Aviv. The explosion occurred in front of a bus stop near the Assaf Harofeh hospital close to the Tzrifin military base, local media are reporting. The Tzrifin camp is one of the largest army bases in central Israel and the bus stop is frequently used by soldiers. Medics are quoted as saying about 30 have been injured, 15 of them seriously. Israeli police have described the explosion as a "terrorist attack" and say the bomber may have been a woman. A statement from Prime Minister Ariel Sharon, who is in New Delhi on an official visit to India, blamed the Palestinian Authority for the attack. "This attack further indicates that the Palestinian Authority is doing nothing to rein in the Palestinian infrastructure of terror," it said. The Israeli government routinely holds the PA responsible for attacks by any Palestinian resistance groups. **Retaliation expected*** No one has yet claimed responsibility for the bombing. But the Palestinian resistance group Hamas had threatened to retaliate for a recent wave of killings of its activists and civilians by the Jewish state. "This is the result of what Sharon has done," said Usama Hamdan, a Hamas spokesman in Lebanon. "He destroyed the peace plan and he has no one else to blame for this attack." "These attacks are likely to continue until Sharon realizes he must stop the assassinations and the killings of Palestinians," he told Aljazeera. The Tel Aviv bombing comes three days after a failed Israeli assassination attempt against the spiritual leader of the Palestinian resistance group Hamas, Shaikh Ahmad Yasin. **PHOTO CAPTION*** A Palestinian man weeps while entering a hospital with a wounded baby, after an Israeli missile hit a Palestinian house in a densely populated area of Gaza City, September 6, 2003. (REUTERS/Suhaib Salem)