JERUSALEM: Israeli security forces on Tuesday killed two alleged Palestinian stabbers, and two Palestinian boys stabbed and moderately wounded a security guard on a train, police said, as violence returned to Jerusalem after a two-week lull.

Jerusalem had been relatively calm over the last two weeks as the focus of a two-month wave of Palestinian attacks, mainly stabbings, shifted to the West Bank, where Israeli troops have also regularly clashed with Palestinian protesters.

Most of the Palestinian attackers have been in their late teens or early 20s. On Tuesday, a 13-year-old Palestinian boy went on trial before a Jerusalem court over a stabbing last month that fueled a high-profile media war.

In the first attack Tuesday, police said two Palestinian relatives, believed to be about 12 and 13 years old, stabbed a security guard on a train in east Jerusalem. The guard was moderately wounded but shot the younger assailant. Passengers subdued the other, police said. The wounded boy was being treated at a hospital.

An amateur video that surfaced on a Palestinian website showed plainclothes Israeli security forces wrestling a young boy, presumably one of the attackers, to the ground and taking off his clothes and shoes. The boy was stripped to his underwear as the security men shouted at him.

Later Tuesday, Israeli forces killed a 37-year-old Palestinian man outside the Old City as he allegedly chased guards while wielding a knife, police said. Israeli police said forces foiled an additional attack in Abu Dis, an Arab neighborhood in east Jerusalem. Police spokeswoman Luba Samri said a Palestinian tried to stab forces at a checkpoint before he was shot dead.

Jerusalem had been relatively quiet for the past two weeks.