Gaza: Witnesses and officials say Israeli shells have struck the UN headquarters, a tower that houses various media organisations and a hospital in Gaza.

The UN compound has been serving as a shelter for hundreds of people fleeing Israel's devastating offensive in Gaza. UN spokesman Chris Gunness says at least three people were wounded.

The entire area is engulfed in smoke and it's not clear whether anyone is still inside the compound.

The compound includes the headquarters of the UN agency for Palestinian refugees, a school and other offices. Gunness says large amounts of aid supplies, as well as fuel trucks, could soon be destroyed.

The attack came as UN chief Ban Ki-moon was in Israel trying to promote a cease-fire.

Media tower attacked

An explosion blasted a tower block in the city of Gaza on Thursday that houses the offices of Reuters and several other media organisations.

Colleagues said a journalist for the Abu Dhabi television channel had been wounded.

Reuters journalists working there at the time said an Israeli missile or shell appeared to have struck the southern side of the 13th floor of the Al-Shurouq Tower in the city centre.

Reuters evacuated the bureau, though a live camera feed that has been providing images from Gaza throughout the war continued to function. Live television images from another site showed smoke pouring from the upper floors of the 16-storey building.

Two employees of Abu Dhabi TV's Gaza office on the 14th floor have been wounded in the attack, an Abu Dhabi TV official confirmed.

Ibrahim Al Ahmed, head of Abu Dhabi TV confirmed to Gulf News that the Al Shurooq building had been hit by Israeli fire, causing minor injuries to two of its employees.

“The Gaza office has fewer than ten employees,'' he said. Abu Dhabi TV also has offices in Ramallah and Jerusalem.

The 13th floor houses a local television production company. The Reuters bureau is on the 12th floor. Reuters journalists on the spot said they had not been aware of any presence of armed men in the building beforehand.

An Israeli army spokesman had spoken with Reuters staff in Jerusalem shortly before the explosion to check the location of the Reuters bureau in Gaza.

Reuters had provided the coordinates of its office to the army at the start of the war and was assured on several occasions that it was not a target.

An army spokeswoman said after the blast that she was checking. She said troops were engaged with Hamas guerrillas in exchanges of fire in the city and said fighters had taken over a media office in the same area late on Wednesday.

During the US assault on Baghdad in April 2003, a Reuters cameraman was killed and three colleagues were wounded when a US tank fired at the Reuters bureau in the Palestine Hotel. A Spanish television cameraman was also killed.

Hospital wing on fire

Meanwhile, a wing of a hospital in Gaza caught fire on Thursday after an Israeli strike, witnesses said.

It was not immediately clear whether there were any injuries, they said. The strike occurred near the Al Quds Hospital in the southwestern neighbourhood of Tal Al-Hawa, where hundreds of people had taken shelter from advancing Israeli tanks in the early morning hours.

With imputs from Abbas Al Lawati, Staff Reporter.