A Palestinian woman argues with an Israeli border policeman near the scene where a Palestinian woman and teenage boy, who the Israeli military said tried to stab security forces, were shot dead by Israeli police at a checkpoint near Ramallah. (Ammar Awad/Reuters)

A young Palestinian mother of two and her teenage brother were shot dead by Israeli forces at a busy checkpoint between Jerusalem and Ramallah on Wednesday.

Israeli police said the sister and brother were going to attack security officers with knives. Their relatives said they must have been lost.

Shortly after the incident, Israeli security forces released photographs showing new kitchen knives that they said were used in the attempted assault. Pictures taken by Palestinian photographers showed the two lying dead on the ground side by side. Although the area is monitored by multiple security cameras, no official footage was released.

Palestinian vendors in the area said they noticed the woman walking the wrong way, against traffic in a car lane, toward the soldiers.

“I heard shouting and curses,” said a young man selling plums. He said the siblings were beside each other when they were shot. The fruit vendor said he counted a dozen or more shots fired.

Israeli police and the Palestinian Health Ministry identified the woman as Maram Salih Hassan Abu Ismail, 23, who lived with her husband in the West Bank village of Beit Surik, just outside Ramallah. Relatives said her brother was Ibrahim Taha, 15.

The incident followed a week of relative quiet, despite fears by Israeli authorities that the wave of violent attacks that started in October and had begun to taper off would flare up during the Jewish holiday of Passover.

Last week, a Palestinian from a well-to-do family near Bethlehem blew himself up on a Jerusalem city bus, injuring 20 Israelis.

There have been hundreds of attacks and attempted assaults by Palestinians against Israeli soldiers and civilians over the past seven months. Most of the assailants have been young males, but there also have been teenage girls and women. This case is unusual because it involves a mother and her sibling.

“The two entered the area used by vehicles on foot. The woman had her hand inside her purse, and the man’s hands were behind his back holding something,” said Israeli police spokeswoman Luba Samri.

Samri said the siblings approached officers at a fast pace and kept moving even after they were told several times to stop.

“The female terrorist stopped a short distance from the officers, then walked the other way with the man. When she suddenly turned around to face the officers, she pulled a knife that was in her purse and threw it at the officers,” Samri said.

Israeli officers stationed at the checkpoint shot and killed them, Samri said. A knife was later found tucked into the man’s belt.

Samri said Israeli police have been out in full force for the week of Passover, especially in Jerusalem and the seam line areas between Israel and the West Bank.

In her hometown of Qatanna, the mother’s family began to gather in a mourning hall. Her uncle, Yusri Hamad Taha, said his niece and nephew were on their way to a medical appointment in Jerusalem, which required them to get travel permits. He denied that they would attack soldiers.

“The Israelis shot them in cold blood and threw the knives down,” the uncle said. “It is nothing new.”

As he was speaking, an altercation broke out as a young man entered the hall carrying posters commemorating the siblings as martyrs and offering condolences from the Islamic Jihad, a paramilitary group in the West Bank and Gaza, which is branded a terrorist group by Israel, the United States and the European Union.

Some men tore down the posters as others plastered them on the walls.

A few miles away in Beit Surik, relatives of the slain woman’s husband also gathered to mourn. The Abu Ismail men said the husband and wife had been arguing lately. “She was mad at her husband and had been living with her father for the last two weeks,” said Barakat Abu Ismail, a cousin.

They denied the separation may have driven the woman to confront Israeli soldiers. In some other cases, Israeli intelligence officials and relatives of slain Palestinians have speculated that assailants were less motivated by Palestinian nationalism than by personal problems.

The family said Abu Ismail leaves behind two daughters, ages 3 and 5.

“But hypothetically, even if she did have a knife, why did the Israelis have to shoot them both?” said brother-in-law Rafat Abu Ismail. “And hypothetically, if she did throw a knife, why did they have to kill her?”

Asked if she had political motives, the men shook their heads.

Since Oct. 1, Palestinians have carried out hundreds of stabbing, shooting and vehicular attacks against Israeli civilians, soldiers and police officers in Israel and the West Bank. About 29 Israelis and four foreign nationals, including two Americans, have been killed in the attacks. More than 184 Palestinians have been killed, more than half carrying out or attempting attacks against Israelis and the rest in clashes with Israeli forces.

Sufian Taha contributed to this report.