United Nations arms experts have visited a laboratory and a munitions factory near Baghdad, on the second day of their hunt for suspected Iraqi weapons of mass destruction.

Inspectors' remit and task

Unrestricted inspection rights Can report any obstruction to the UN First task to assess infrastructure left behind in 1998 They will set up monitoring equipment Are able to take witnesses out of Iraq Click here to read Q&A on inspections

Two teams set off from their Baghdad headquarters followed by dozens of journalists, but Iraqi guards prevented the reporters from entering the facilities.

After the inspections resumed on Wednesday, the experts said they had been given full co-operation by the Iraqis.

But US Deputy Defence Secretary Paul Wolfowitz said there had to be a genuine change of heart by the Iraqi leader for the programme to succeed.

On Thursday one of the UN teams visited an animal vaccine production plant at al-Dora, south of the capital.

The BBC's Ben Brown in Baghdad says the plant has a documented history of biological weapons production, including anthrax.

Fine tooth comb

When weapons inspectors were last in Iraq in the 1990s they visited and disabled part of the al-Dora plant. But, our correspondent adds, there is a lingering suspicion that biological weapons could still be manufactured there.

The weapons inspectors peered into storage tanks, and looked over pipes and other fixtures for signs of any military research.

The US suspects weapons are produced at al-Dora

Another team went to the al-Nasser factory, north of Baghdad, which produces both ammunition and civilian machinery.

On Wednesday, the inspectors visited the al-Tahadi factory in the al-Rashad suburb, north-east of Baghdad, and a graphite plant at al-Amariyah, south-west of the capital.

After Wednesday's inspections, Jacques Baute of the International Atomic Energy Agency (IAEA), who led one of the groups, said: "The team was able to complete the inspection work as it planned with the co-operation of the Iraqi side, and we had access to what we wanted to see."

Chief UN Weapons Inspector Hans Blix said it was a "good start" - but cautioned that a long process was just beginning and it was too early to say what the final result would be.

"I wouldn't want to predict too much simply because we have had one day without conflict."

Caution

Maintaining US pressure on Baghdad, the Deputy Defence Secretary said there had to be a genuine change of heart by President Saddam Hussein for the weapons inspections to succeed.

The experts have new equipment

Mr Wolfowitz - one of the leading hardliners in the Bush administration - warned that if Baghdad continued to maintain that it had no weapons of mass destruction, then that would be a fairly strong sign of non co-operation.

The inspectors are using state-of-the-art technology to try to find out whether Iraq has any weapons of mass destruction.

Their findings could determine whether the US carries out its threat to lead a military assault on Iraq.

	:	Iraq spotlight
Click to see maps of Iraq's suspected weapons sites

The inspections were authorised by the UN Security Council in a resolution unanimously agreed earlier this month, which aims to compel Iraq to disarm or face "serious consequences".

In the days ahead, the UN inspectors are expected to spread out over Iraq in search of mobile laboratories, underground factories and other signs of banned Iraqi weapons production.

Under the terms of the resolution, Baghdad has until 8 December to produce a list of any nuclear, chemical or biological weapons in its arsenal - the accuracy of which weapons inspectors will be asked to verify.