A building sheltering hundreds of displaced people in the city of Khan Younis was hit by Israeli tank fire on Wednesday, according to the UN, as Israeli forces ramped up attacks on southern Gaza, forcing streams of Palestinians to flee the neighborhood, writes CNN.

Wreaths of smoke hung over the UN shelter, after a huge blaze broke out at the UNRWA Khan Younis Training Center, video obtained by CNN showed.

“Buildings ablaze and mass casualties. Safe access to and from the center has been denied for two days. People are trapped”, Thomas White, the director of UNRWA Affairs, said on X.

At least 9 people were killed and another 75 injured, White said, adding that a team from his agency and the World Health Organization were trying to reach the site. He said the building shelters 800 people. UNRWA Commissioner-General Philippe Lazzarini said on X that the entire Khan Younis Training Center, one of the largest UNRWA facilities in Gaza, was sheltering 30,000 people, and is clearly marked as a UN site.

In a statement, the Israel Defense Forces (IDF) said it had “currently” ruled out that the incident was “the result of an aerial or artillery strike by the IDF”. It said a “thorough review of the operations of the forces in the vicinity is underway,” adding that it is “examining the possibility that the strike was a result of Hamas fire”.