Three people were detained and a total of 345 pen-guns seized in the operation on a factory near the northeastern Mediterranean port city of Barcelona.

The weapons were apparently genuine 0.22 calibre pistols in the form of pens and could be deadly at close range, although the short barrel length meant their accuracy was limited.

The pen guns were being sold on the black market for 300 eurosdollars), mainly to collectors, and were generally not destined for individuals intending to commit crimes, police said.

Those arrested -- two men and a woman -- are being held on charges of manufacturing illegal weapons. They were also said to be in possession of classic small arms.

WAR.WIRE