Cambodia's nine opposition- aligned trade unions warned Wednesday that they would lead a weeklong strike from March 12 to 19 if the court does not free 21 detained protesters and the government does not raise minimum wages for garment workers to $160, a union leader said.

Pav Sina, president of the Collective Union of Movement of Workers, said the leaders of nine trade unions met Wednesday and approved of the protest schedule, adding that the unions would print 100,000 copies of a leaflet announcing the strike date and stating the demands.

"The demands include calls for the release of 21 detained protesters, a $160 minimum wage for garment workers and an end to the government's temporary ban on demonstrations," he said after the meeting.

On Tuesday, the Appeal Court refused to grant bail to the 21 protesters who were detained following violent clashes during garment workers' protests for higher salaries early last month that left 4 people dead.

The government has imposed a temporary ban on demonstrations since then.

Kheng Tito, spokesman for the National Military Police, said if the protest is allowed by local authorities, security forces have duties to protect the participants.

"But if the protest is outlawed and causes violence or social disorder, security forces will take measures to maintain social security and public order," he told Xinhua.

Many protests had been held by the country's main opposition Cambodia National Rescue Party (CNRP) since the disputed election in July last year.

The poll results showed that Prime Minister Hun Sen's ruling party won 68 parliamentary seats and Sam Rainsy's opposition CNRP got the remaining 55 seats.

Claiming serious irregularities, the opposition refused to accept the outcome and has boycotted parliament and held protests, demanding the resignation of Hun Sen and a re-election.

Opposition-aligned trade unions have backed up the opposition party through leading garment workers to stage protests to demand higher wages even though the government has already raised monthly minimum wages for workers from $80 to $100 from this month.

The garment and shoe industry comprise more than 900 factories with about 600,000 workers. The sector is the kingdom's largest foreign exchange earner which generated some $5.53 billion in revenues last year.