Thousands of protesters have continued to take to the streets of Guatemala's capital to pressure President Otto Perez Molina to resign over his alleged involvement in a major corruption scandal, as the government comptrollers' office urged him to quit "to avoid greater social unrest".

A national strike was also launched on Thursday over the country's largest political crisis in recent history, a day after the Supreme Court ruled that Congress could strip him of immunity from prosecution over a multimillion-dollar customs fraud scheme.

Businesses and government offices were closed as Al Jazeera's David Mercer, reporting from Guatemala City, said that "thousands, if not tens of thousands" of demonstrators gathered in the capital's centre, including around the national palace, on Thursday.

"There have been four months of protests, which have culminated today," he said.

"There is a real show of force calling upon all politicians to clean up their act and bring transparency."

Ministers resigning

The attorney general, who is trying to launch the impeachment process against Molina, urged Molina to leave his post "to prevent ungovernability that could destabilise the nation".

Five of Molina's 13 cabinet ministers have resigned over the corruption scandal since Friday, as have eight vice-ministers, two secretaries and other government officials.

His administration's former ministers of defence and the interior, who had resigned recently over the graft allegations, have both left Guatemala, the country's immigration service confirmed.

Molina has not spoken publicly since Sunday, when he denied any involvement in the corruption scandal and said emphatically that he would not resign.

On Wednesday, Perez Molina's former vice president, Roxana Baldetti, was denied bail and ordered to remain in jail pending trial on charges of conspiracy, customs fraud and bribery.

She is accused of accepting $3.7m in bribes from businessmen to evade import duties. The scandal forced her from office.

Source: Al Jazeera and agencies