Activists in Egypt have begun a day of civil disobedience to mark the first anniversary since the toppling Hosni Mubarak, the former president.
The call for strikes in universities and workplaces on Saturday comes after a series of protests aimed at pressuring the military to transfer power immediately to civilians.
The demonstrators say the military should hand power to parliament, which was elected over three rounds in November and December, or to a civilian council, ahead of presidential elections set to take place before the end of June.
The military, headed by Mubarak's long-time defence minister Field Marshal Hussein Tantawi, has said it will deploy additional troops across the country in response to the calls for a day of disobedience.
Tareq al-Khouly, an organiser of the April 6 youth group, said the plan was for a one-day strike which could be extended.
'Support the strikes'
In a joint statement on Friday, the protesting groups urged Egyptians "to support these strikes in order to end the unjust rule and build a nation in which justice, freedom and dignity prevail".
The call for strikes and protests has divided the country's political forces, with the Muslim Brotherhood, the big winner in the recent parliamentary elections, coming out against it.
Many Egyptians complain that the economy has been battered by the lack of security and deadly violence in the wake of the 18-day revolt that forced Mubarak to resign on February 11 last year.
On Friday, thousands of protesters marched through Cairo's streets to bypass military cordons and reach the defence ministry, chanting "Down with military rule!"
In a statement read out on state television late on Friday, the ruling Supreme Council of the Armed Forces (SCAF) said it would not bow to threats or plots against the state.
"We will never yield to threats, and we will never give in to pressure," the SCAF said.
"We tell you quite frankly that our dear Egypt faces plans aimed at striking at the heart of our revolution.
"We are facing plots against the nation aiming to undermine the institutions of the Egyptian state, and to topple the state itself so that chaos reigns."
The SCAF statement also said it was determined to transfer power to an elected civilian body.
"We have kept the first promise and returned legislative power to the people's assembly," it said, adding that the parliamentary election took place in an atmosphere of "liberty and integrity".
"Presidential power will pass to the president of the republic after the election ending the period of transition, and your faithful army will revert to its original role," the statement said.