Israel smashes into Palestinian siege HQ

An Israeli army bulldozer has punched a hole in the side of the Palestinian headquarters building in the West Bank city of Hebron.

It is the fourth day of the building's siege, as the Israelis demand the surrender of gunmen inside.

The Palestinian leadership has condemned the offensive as "an attempt to sabotage peace efforts."

It has released a statement to the world leaders attending the G-8 summit in Canada appealing for them to "send observers to the region to ensure implementation of a ceasefire."

Israeli troops now control seven of the eight main West Bank cities and towns.

Soldiers and border police have also arrested six Palestinian in villages near Jerusalem, Bethlehem and Hebron, describing them as "suspected in terror activity."

An armored bulldozer rumbled up to the fortress-like Palestinian headquarters building and started knocking down the exterior wall, witnesses say.

A day earlier, Israeli helicopters fired four missiles at the four-story structure. Soldiers outside warned that they would go in and extract the gunmen if they did not give themselves up.

The building is already showing scars from Israeli gunfire. Tank shells punched large holes in the walls at ground level.