Thousands of workers have jammed the streets of the main cities of Medan, Surabaya and Cimahi in massive protests over the newly set minimum wages, which they say are below the cost of living.

In the protests on Monday several workers were injured in Medan when security personnel tried to hold back the crowd.

The fence of the East Java governor's office was torn down after a request made on behalf of the estimated 10,000 workers gathered there, to meet Governor Imam Utomo, was refused. His staff members had relayed the message that the governor was too busy preparing for the arrival of President Susilo Bambang Yudhoyono.

The hundreds of police on duty were outnumbered by the protesters, who had been arriving in trucks from Surabaya, Sidoarjo, Mojokerto and Pasuruan since early morning.

Once they entered the governor's office compound, the protesters, shouting their demands, lowered their flag to half-mast in a reflection of their "grief" over the new minimum wage -- while others stamped on plaques at the governor's office.

The protest was the latest, and the biggest, in the province following the governor's recent decision to raise the minimum wage from Rp 578,000 (US$57.80) per month to Rp 665,000 -- much lower than the workers' demand for Rp 1,330,000 per month. The new wage will take effect on Jan. 1.

"We staged protests before but were ignored. So we staged a massive protest to show the governor that workers in East Java reject the new minimum wage," said Jamaluddin, a protester.

Thousands of workers in Medan, however, were not as successful in their descent on Deputy Governor Rudolf Pardede's office.

Several workers, grouped under the North Sumatra Workers General Action, were injured, allegedly after being pushed by police officers.

The group's coordinator, Baginda Harahap, regretted the incident, which he said could have been avoided if the administration had taken seriously the workers' dissatisfaction over the new minimum wage of Rp 737,794 per month, from the previous Rp 600,000 per month.

The workers earlier proposed a new minimum wage of Rp 1.2 million for single workers and Rp 1.5 million for married ones.

North Sumatra administration spokesman Eddy Syofian said the administration understood the workers' demand but it could not ignore the difficult times faced by businesspeople.

In the West Java town of Cimahi, hundreds of workers demanded on Monday that West Java Governor Danny Setiawan revoke the city's new minimum wage of Rp 715,000, from the previous Rp 601,000