CAIRO — The organizers of anti-government protests that brought millions of Egyptians into the streets this weekend today gave Islamist President Mohammed Morsi until Tuesday afternoon to step down or else it will hike up its campaign.

In a sign of Morsi’s growing isolation, five Cabinet ministers met today to consider resigning their posts and joining the protest movement, the state news agency said. The meeting gathered the communications, legal affairs, environment, tourism and water utilities ministers, MENA reported.

The ultimatum issued today by Tamarod, the protest organizers, increases pressure on Morsi a day after the opposition’s massive show of force on the streets, with millions packing Cairo’s Tahrir Square, the streets outside the presidential palace and main squares in cities around the country on the anniversary of Morsi’s inauguration.

The main rallies in Cairo were largely peaceful, but deadly violence broke out in several parts of the country, often when marchers came under gunfire, apparently from Islamists. At least 16 people were killed and more than 780 injured.

Tamarod, Arabic for “Rebel,” issued a statement giving Morsi until 5 p.m. Tuesday to step down and pave the way for early presidential elections or else it would bring the crowds back out. Protesters were already gearing up for new rallies today.

Morsi has said he will not quit, saying that street action must not be allowed to remove an elected president or else the same could happen to future presidents.