Updated

U.N. inspectors on Saturday visited uranium storage sites and an Iraqi complex that made munitions for chemical or biological weapons.

The inspection came as Iraq prepared to hand over a huge report detailing its past and current arsenal.

Some two dozen U.N. monitors have been working in Iraq the past two weeks. Up to 35 new inspectors are scheduled to arrive Sunday, and as many as eight helicopters are expected soon, enabling the arms investigators to stage surprise visits farther afield, U.N. officials say.

After a two-day break for a Muslim holiday, one U.N. team visited the al-Quds General Company for Mechanical Industries at Iskandariya, 25 miles south of Baghdad.

In the 1980s, the factory was part of Iraq's medium-range missile program, now prohibited under U.N. resolutions.

The plant also made "special munitions," bombs designed to hold chemical or biological weapons.

The team presumably was checking the site to ensure that similar activities have not resumed in the four years since a previous U.N. monitoring effort was suspended. As usual, the U.N. inspection agency issued no immediate information about Saturday's visit.

Hamid al-Azawi, director of al-Quds, said his company is involved in mechanical and physics research for short-range artillery and rocket launchers. He said the company was inaugurated in September after splitting from another company, Milad. He did not give information about Milad's activities.

The 15 inspectors departed after about 3 hours. "We dealt with them with total transparency and they were happy with our answers," al-Azawi told reporters.

A second group of inspectors visited "uranium storage sites" near the major Iraqi nuclear research center at al-Tuwaitha, 15 miles southeast of Baghdad, Iraqi Information Ministry officials said.

They may have been interested in large amounts of low-grade uranium from an Iraqi research reactor. That uranium has been sealed and under monitoring by the International Atomic Energy Agency since the 1990s. The fuel could be made bomb-grade if the major technological hurdles of efficient enrichment were overcome — something Iraq was unable to do in the past.

The inspectors have returned under a new U.N. Security Council resolution mandating that Iraq surrender any weapons of mass destruction and shut down any programs to produce chemical, biological or nuclear weapons.

The Iraqis, who deny they have such weapons or programs, have a Sunday deadline to make a full declaration on the subject. Saturday, Iraqi officials displayed more than 12,000 pages of documents to reporters. The report was expected to be handed over to U.N. officials in Baghdad late in the day.

By the end of December, 80 to 100 U.N. workers will be making daily inspections in Iraq.

So far, the U.N. teams have largely revisited sites inspected by their predecessors in the 1990s to ensure that equipment is where it should be and producing non-proscribed items.