A ship that was carrying weapons and ammunition destined for Zimbabwe lifted anchor and sailed from Durban less than an hour after the Durban High Court ordered that its controversial cargo cannot be transported across South Africa to that country.

The An Yue Jiang lifted anchor between 6pm and 7pm on Friday evening.

Several sources, who spoke on condition of anonymity, confirmed that the ship had set sail from the outer anchorage off the port of Durban.

The ship's master, who earlier this week identified himself as captain Sunaijun, could not be connected by radio phone. Operators in Cape Town reported that calls to the ship were going unanswered.

It was not immediately known where the vessel, owned by Chinese state owned company Cosco Group, was headed.

Nicole Fritz, the director of the Southern African Litigation Centre, said she had been informed that as the sheriff of the Durban High Court approached the vessel, it lifted anchor and began sailing.

She said that if the ship went to Mozambique, the SALC would seek to implement similar legal action as implemented in Durban.

Durban Port Captain Ricky Bhikraj referred all comment to Transnet spokesman John Dludlu, who could not be reached for comment.

Earlier on Friday the Durban High Court ordered that the arms shipment destined may be offloaded in Durban's harbour but that the controversial cargo could not be transported across South Africa to that country.

Anglican bishop Rubin Phillips with Patrick Kearney, a former activist and executive of the Diakonia Council of Churches, applied to the Durban High Court to prevent the weapons from reaching Zimbabwe.

The papers were lodged with Judge Kate Pillay in chambers shortly before 5pm.

About an hour later their attorney Ranjit Purshotam emerged from the court and announced that Judge Pillay had ruled in favour of the application - effectively barring the movement of the arms to Zimbabwe.

"There is an interdict in place at the moment which prohibits the conveyance of arms and ammunition across the territory of South Africa.

It is an interim order in place which will be in place until next Friday," he said.

Their legal action was being sought in terms of the National Conventional Arms Control Act (NCACC), which "requires that any transfer of arms be authorised by a permit issued on terms of the NCACC".

On Monday South African defence secretary January Masilela, who chairs the scrutiny committee of the NCACC, issued the conveyance permit.

The An Yue Jiang has been at anchor off Durban since Monday.

Noseweek editor Martin Welz told Sapa on Wednesday that "the cargo ship was openly delivering a containment of arms for Zimbabwe".

He said he had copies of all the documents, including the bill of lading and a packing list.

The controversial cargo packed into 3080 cases allegedly includes three million rounds of 7.62mm bullets (used with the AK47 assault rifle), 69 rocket propelled grenades, as well as mortar bombs and tubes.

The cargo is, according to the documentation, valued at R9.88 million.

The seven respondents in the case are the NCACC, the Minister of Defence, the Secretary of Defence, the Minister of Foreign Affairs, a company called AB Logistics, the Durban Port Captain and Transnet. Pillay ordered that they return to court next Friday.

Purshotam said that the arms and weapons would be off loaded off the ship and placed in "secure storage pending the final resolution of this matter."

He said that he believed that the ship would dock in Durban's harbour within the next 24 hours.

Asked about the SA Transport and Allied Workers Union's (Satawu) announcement on Thursday that its members would not offload the ship, Purshotam said: "I think we appreciate the support which the unions have demonstrated. The main thing to do at this time is to ensure that the cargo is unloaded because we would not like for the vessel to cut and loose and go to another port."

Speaking to the media after the decision was handed down Kearney said: I think we believe it would be highly irresponsible for additional arms to be made available in that kind of situation where we have an election that seems to have collapsed. We still don't know who the president of Zimbabwe is."

Phillip's said: "It's a matter of principal that we do not, in terms of our own laws, allow armaments to pass through our country to any government that contributes to human rights abuses. That's not me saying that. That's a statute of our country."

He conceded that the legal action could mean that future shipments of arms to Zimbabwe would go through other countries such as Mozambique.