JOHANNESBURG, South Africa - South African police seized a shipment of guns they believe were bound for Somalia to be used against pirates in a possible a violation of a UN arms embargo, authorities said Tuesday.

Eight assault rifles fitted with telescopic and silencing devices, two AK-47s, two shotguns and a revolver were confiscated from a home near the port city of Durban. Police had been tracking the shipment and four people -- two South Africans and two foreigners -- were arrested in the Dec. 23 raid and are out on bail, said South African police spokesman Vincent Mdunge.

Police are trying to determine whether a port official helped move the weapons. Mdunge would not disclose the two foreigners' nationalities.

The seizure follows weeks of speculation over a controversial program, involving an ex-CIA deputy station chief and a former U.S. ambassador, to train and fund antipiracy forces in Somalia. Police in South Africa drew no link between the training program and the arms seizure.

Mdunge would not name the shippers, but said investigators believe that the weapons were being sent to Somalia for use against pirates. It was unclear whether the shippers had the proper permits to send the weapons to Somalia, Mdunge said, adding that he didn't know where the weapons were shipped from and whether they were destined for a private company or the Somali government.

The anarchic country's long coastline is dotted with havens of pirates who prey on vital shipping routes.

Those involved with the antipiracy program have refused to say who is funding it, other than that it is a Muslim country, but have repeatedly insisted no guns would be sent to Somalia in violation of the UN arms embargo.

Numerous Somali officials have identified Uganda-based Saracen International as the security contractor doing the training. But Bill Pelser, the chief executive of Saracen International, has denied his company is involved and says it is another company of the same name registered in Lebanon. Lebanese authorities say they have no record of such a company.

The four men detained in the raid are to appear in court on Feb. 7.