Israeli police clash with mourners as they carry the casket of Shireen Abu Akleh during her funeral in east Jerusalem. File / AP

Israeli riot police on Friday pushed and beat Pallbearers at the funeral for slain Al Jazeera journalist Shireen Abu Akleh, causing them to briefly drop the casket in a shocking start to a procession that turned into perhaps the largest display of Palestinian nationalism in Jerusalem in a generation.

The scenes of violence were likely to add to the sense of grief and outrage across the Arab world that has followed the death of Abu Akleh, who witnesses say was killed by Israeli troops Wednesday during a raid in the occupied West Bank. They also illustrated the deep sensitivities over east Jerusalem - which is claimed by both Israel and the Palestinians and has sparked repeated rounds of violence.

Israeli police decided on Saturday to investigate the conduct of their officers during the journalist’s funeral.

"The Israel Police supports its police officers, but as a professional organization that seeks to learn and improve, it will also draw lessons from the incident,” the statement said.

At the same time, top officials, including Public Security Minister Omer Bar-Lev, appeared to be closing ranks in support of the officers, reiterating earlier claims that the troops at the funeral acted in response to violence.

US Secretary of State Antony Blinken called on Sunday for a "credible" investigation into the death of Palestinian journalist Shireen Abu Akleh as he offered condolences to her family.

Blinken said he spoke with the brother of Shireen Abu Akleh, who was a US citizen, during his flight on Saturday to Berlin for a meeting of Nato foreign ministers.

"I had a chance to express deep condolences for her loss, our deep respect for the work that she did as a journalist for many years," Blinken told reporters in Berlin.

He said he discussed the "need to have an immediate and a credible investigation into the circumstances surrounding her death."

He said the Al Jazeera journalist was "widely respected around the world".

Blinken offered the support of US diplomats in Jerusalem to the family of Abu Akleh, who also held US citizenship, a US official said.

Al Jazeera said Israel shot her "in cold blood." Israel, which has been facing a series of attacks, initially said Palestinian gunmen could be to blame before backtracking and promising to investigate.

Agencies