"In late May, we obtained information that... terrorists were looking to buy these warheads and were offering 5,000 dollars (4,000 euros) per unit (to potential sellers)," General Marek Dukaczewsky told a news conference.

"Among the names of potential buyers that were circulating, we identified those of people linked to terrorist activities," he said.

"We do not have information indicating that terrorists have any (such weapons) in their possession but the fact they were seeking them allows us to suppose that they do," the general said.

Washington announced on Thursday that Polish troops had discovered more than a dozen warheads containing mustard or sarin gas in Iraq, a report later confirmed by Polish Defence Minister Jerzy Szmajdzinski.

In late June, Dukaczewsky said, Polish military intelligence services were offered a chance to purchase chemical weapons and proceeded to buy 17 Soviet-manufactured 122-milimetre warheads, all of which are thought to contain sarin gas.

He said the warheads "could be used as chemical mines or in suicide attacks".

"It is important to note that this ammunition was transported from some depot and buried in order to avoid discovery by United Nations inspectors," the intelligence chief said.

Dukaczewsky said that research was continuing into the banned weapons.

No weapons of mass destruction have yet been found in Iraq, seriously undermining what was the central argument for the United States and Britain for launching their invasion of the country in March 2003.

Poland, one of the staunchest supporters of the US in the Iraq war, patrols a large swathe of the country south of Baghdad, heading a 6,500-strong multinational force including 2,500 Polish troops.

WAR.WIRE