BEIJING (REUTERS) - China created 12.7 million new jobs in urban areas in 2012, the Ministry of Human Resources and Social Security, said on Friday.

The increase from 2011's 12.2 million new urban jobs left China's urban jobless rate steady at 4.1 per cent at the end of 2012 - the 10th straight quarter officials say it has been at that level.

The urban jobless rate is China's only official unemployment indicator, but analysts say it grossly underestimates the true level of unemployment because it excludes about 250 million migrant workers from its surveys.

The National Bureau of Statistics said last week that China had created 11.9 million jobs in 2012 in urban areas. The differing numbers highlight the discrepancies in China's employment data which feed analysts' doubts.

Economists at Nomura in Hong Kong said other data signalled that China's labour market had tightened in the fourth quarter of 2012, with an index of the ratio of urban labour demand to supply rising to 1.08 from 1.05 in Q3 - its highest since the index was first published in 2002.

A group of about 20 migrant workers from Dalian in China's northeastern Liaoning province were demonstrating outside the labour ministry on Friday as the jobless data was presented at a news conference, demanding the ministry help them collect unpaid wages after completing work on a construction project.

China's migrant workers are the backbone of the country's labour force, working mainly in low paid jobs on construction sites and in factories.

Beijing has mandated that minimum wages rise at least 13 per cent a year during the course of the current five-year plan that runs to 2015.

The same plan mandates annual increases in urban and rural household incomes of more than 7 per cent, which would result in them doubling over 10 years.

The labour ministry said on Friday that 25 of China's 32 provinces raised minimum wages at an average of 20.2 per cent in 2012.

In 2011, 24 provinces increased minimum wages by an average of 22 per cent.

In 2010, 30 provinces delivered increases of an average of 22.8 per cent.

The most recent data available shows minimum wages in 2011 ranged from 1,500 yuan (S$297) per month in Shenzhen, the highest, to 870 yuan in Chongqing, the lowest.

The disparity of incomes has become a politically sensitive issue in China over the last decade as the gap between rich and poor has widened into a chasm.

About 13 per cent of China's 1.3 billion people still live on less than US$1.25 (S$1.54) per day according to the United Nations Development Programme and average urban disposable income is just 21,810 yuan a year.