GAZA CITY, Palestinian Territories -- An Israeli air strike on Saturday demolished the 13-floor building housing Qatar-based Al Jazeera television and American news agency The Associated Press in the Gaza Strip, AFP journalists said.

Israel "destroyed Jala Tower in the Gaza Strip, which contains the Al Jazeera and other international press offices," Al Jazeera said in a tweet, with an AP journalist saying the army had warned the tower's owner ahead of the strike.

Al Jazeera broadcast footage showing the building collapsing to the ground after the Israeli air strike, sending up a huge mushroom cloud of dust and debris.

Jawad Mehdi, the owner of the Jala Tower, said an Israeli intelligence officer warned him he had just one hour to ensure the evacuation of the building.

In a phone call with the officer, AFP heard him beg for an extra 10 minutes to allow journalists to retrieve their equipment before leaving.

"Give us ten extra minutes," he urged, but the officer on the other end of the line refused.

Wael Al Dahdouh, Al Jazeera's bureau chief in Gaza told AFP: "It's terrible, very sad, to target the Al Jazeera and other press bureaux".

Israeli air and artillery strikes on Gaza since Monday have killed 139 people including 39 children, and wounded 1,000 more, health officials in the coastal enclave say.