ISLAMABAD: The United Nations on Thursday urged Pakistan to ensure safety for civilians and aid workers during a major military offensive against Taliban militants in the northwestern tribal belt.

'We are very concerned that all who are involved in the military operations must take the absolute first priority to assure safety and security of the civilians,' UN humanitarian coordinator Martin Mogwanja told reporters.

The US-based Human Rights Watch last week said it had received reports of civilian deaths and the destruction of property during the operations.

Around 30,000 troops launched an air and ground offensive against an estimated 10,000 Tehreek-e-Taliban Pakistan (TTP) militants concentrated in South Waziristan, part of the semi-autonomous and lawless tribal belt.

Expressing concerns of humanitarian workers, the UN official said civilians caught in the conflict must be provided safe passage to reach safer areas and that the safety of humanitarian workers should also be ensured.

'We also want to underline that any impact of the conflict on the civilians must be avoided at all costs,' Mogwanja said.

'The civilians have no place in this conflict. Their safety and their safe exit from the areas of conflict must be assured and it is the responsibility of those involved in the conflict to make sure that this happens.'

Mogwanja added: 'Safety and security must also be provided to all the humanitarian workers who are providing humanitarian assistance to the displaced and vulnerable populations.'

The official did not give estimates of collateral damage in the conflict zone saying the United Nations had no access to those areas, but demanded that such access be provided to humanitarian workers.

'It is most particularly essential that the humanitarian organisations should be provided with safe access to the areas of displacement and also to the areas, ultimately, of conflict so that we can provide the necessary assistance, protection and services to the affected population.'

Mogwanja said that fresh displacements of 'thousands of people' were taking place due to 'sporadic' military operations in the northwest Malakand division, home to about three million people, and the Bajaur tribal district.

Kilian Kleinschmidt, a senior UN refugee agency official, said that while about 330,000 displaced people from South Waziristan had been registered, only about 165,000 people had so far been verified by a national database authority.