CAIRO/JERUSALEM, Aug 11 (Reuters) - A prominent Al Jazeera journalist, who had previously been threatened by Israel, was killed along with four colleagues in an Israeli airstrike on Sunday, in an attack condemned by journalists and rights groups.

Israel's military said it targeted and killed Anas Al Sharif, alleging he had headed a Hamas cell and was involved in rocket attacks against Israel.

Al Jazeera rejected the claim and before his death Al Sharif had also rejected earlier claims by Israel that he was connected to Hamas.

Al Sharif, 28, was among a group of four Al Jazeera journalists and an assistant who died in a strike on a tent near Shifa Hospital in eastern Gaza City, Gaza officials and Al Jazeera said. An official at the hospital said two other people were also killed in the strike.

A sixth journalist, Mohammad Al-Khaldi, a local freelance reporter, was also killed in the airstrike, medics at Al Shifa Hospital said on Monday.