JUBA/KHARTOUM - South Sudan accused Sudan of bombing a disputed major oil field "to rubble" on Sunday but Khartoum denied that and said it would not negotiate until Juba withdrew all its troops from the same area. South Sudan's Information Minister Barnaba Marial Benjamin told reporters in Juba the aerial bombardment of the facility - in the Heglig region - had caused serious damage. "They are bombing the central processing facility and the tanks to rubble as we speak," he said. Sudan's state minister for information denied the charge, however, telling Al Jazeera television that Sudan "did not and will not" destroy the oil facilities. Fighting between the two neighbours has already halted production at the facility, depriving Sudan of about h alf of its 115,000-barrel-a-day oil output. Both sides regularly make conflicting claims and limited access to the remote region makes it difficult to independently verify their statements. But the seriousness of the allegations underscored how close the two former civil war foes are to the brink of a full-blown war as the worst fighting since Juba declared its independence in July continued apace. On Tuesday, South Sudan seized control of the Heglig oilfield, drawing an angry response from Khartoum which vowed to recapture the region. On Sunday, South Sudan's military (SPLA) spokesman Philip Aguer said by phone that Sudanese aircraft were continuing efforts to dislodge southern forces from the area, subjecting them to an aerial bombardment. "There has been intensive air bombardment against our position in Heglig since the morning," he said, adding there had been no ground fighting there on Sunday. Sudan's army had also shelled a western part of South Sudan's Upper Nile state, in an apparent attempt to open a new front, he said. A spokesman for Sudan's armed forces did not immediately answer calls to his mobile phone for comment. The Sudanese army said it had entered the Heglig region on Saturday, but South Sudan denied that.