Israel says no action will be taken against those involved in the last year's bombing of Gaza beach that left four Palestinian children dead, saying that it was an accident.

"The ... case has been closed following the completion of a criminal investigation," the Israeli army said in a statement on Thursday.

Cousins Ahed Atef Bakr and Zakaria Ahed Bakr, both aged 10, nine-year-old Mohamed Ramez Bakr and 11-year-old Ismail Mohamed Bakr were playing on the beach in Gaza City when they were hit in strikes witnessed by journalists staying at a beachfront hotel.

Two other cases involving Palestinian deaths during the 50-day Gaza war have also been dropped, but the army said it was launching a criminal investigation into an attack on a cafe that killed nine people.

The Israeli military said that it had ordered criminal investigations into the deaths of nine people in an attack on a Khan Younis cafe on July 9 and into other allegations of abusing a detainee and unlawfully firing at a medical clinic.

It also said charges were filed over alleged looting of Palestinian property by Israeli soldiers.

The incident is among those likely to be presented by the Palestinians to the International Criminal Court as evidence of alleged Israeli war crimes.

On January 16 the ICC announced "a preliminary examination" into Israel's actions over a period including the Gaza war in which about 2,200 Palestinians were killed, mainly civilians.

On the Israeli side 73 people were killed, of them 67 were soldiers.

On April 1, the Palestinians joined the ICC with the goal of trying Israeli leaders over alleged abuses in the Gaza war and alleged crimes relating to the occupation of the West Bank and East Jerusalem.