Findings show that Israeli forces fired the bullets that killed Al-Jazeera reporter Shireen Abu Akleh in May and not indiscriminate firing from Palestinians, a spokesperson for the United Nations human rights office said Friday.

"All information we have gathered ... is consistent with the finding that the shots that killed Abu Akleh and injured her colleague Ali Sammoudi came from Israeli security forces and not from indiscriminate firing by armed Palestinians," U.N. Human Rights office spokesperson Ravina Shamdasani told reporters in Geneva.

"It is deeply disturbing that Israeli authorities have not conducted a criminal investigation," Shamdasani added.

Shireen Abu Akleh, 51, was born in Jerusalem. She began working for Al-Jazeera in 1997 and regularly reported on camera from across the Palestinian territories.

A well-known American-Palestinian reporter for Al-Jazeera’s Arabic language channel, Akleh was among the reporters who rushed to the northern city of Jenin in the occupied West Bank to cover an Israeli raid before she was shot dead by Israeli forces on May 11, according to the Palestinian officials and her employer, Al-Jazeera.

Israeli and Palestinian officials have exchanged recriminations over the incident, which has heightened tensions. Israel has denied that any Israeli soldier "targeted a journalist."

An Arab nongovernmental organization (NGO), on the other hand, had documented 148 Israeli rights violations against Palestinian journalists in the occupied Palestinian territories last month. In a statement, the Journalists Support Committee said the month of May witnessed a surge in attacks on Palestinian journalists by Israeli forces and settlers.

It termed the attacks as "an attempt to prevent Palestinian journalists from covering Israeli assaults against Palestinians and their holy sites."