By Dan Isaacs BBC, Lagos

Oil workers who were held hostage on rigs off the Nigerian coast for almost two weeks have been arriving back safely on the mainland.

Among some 100 foreign nationals held were about 35 Britons and 17 Americans.

This siege has been a public relations disaster

They were caught up in a protest by local staff demanding better working conditions and the reinstatement of sacked colleagues.

Evacuating almost 400 people from these offshore rigs has not been a quick operation.

Both helicopters and boats are taking part in the process, which is now well under way.

Those arriving back on the mainland are saying little about their ordeal to waiting journalists, and are being moved swiftly onto buses and driven away.

This was not that bad - sometimes it's worse Luis Peraza Freed hostage

There is clearly an attempt at damage limitation by restricting media access to the freed hostages.

This siege has been a public relations disaster, not only for the company operating the rigs, but for the Nigerian oil industry as a whole, which already faces serious unrest and threats against multinational oil facilities by militant groups elsewhere in the Niger delta.

At the height of the violence in the region a few weeks ago, the major oil producers were forced to evacuate many of their staff and cut back production by 40%.

Underlying this instability is the frustration amongst local communities that foreign companies make huge profits out of the oil industry and put back little into what is one of the least developed parts of the country.