Submitting to some of the demands of anti-government protesters, the king of Bahrain has ordered the release of some imprisoned political dissidents.

King Hamad bin Isa al-Khalifah’s decree came as opposition parties are calling for a rally in the capital Manama later Tuesday – their first official expression of support for the protesters who have camped out at Pearl Square for the past week.

No details of the planned prisoner release were provided, however the Wall Street Journal reported that the principal opposition group, al-Wefaq, said the decree included 25 Shiite activists on trial for allegedly plotting against the state.

Bahrain’s population is majority Shia, but they are ruled by Sunni elite.

No official statement has been made yet but we have been promised that the political prisoners will be included in the pardon. We will, of course, review our position after the prisoners are released, but this is a positive step, said Abdul Jalil Khalil, an al-Wefaq lawmaker.

One of those 25 political prisoners is reportedly opposition leader Hassan Meshaima, who is scheduled to return to Bahrain later today from self-imposed exile in England.

Meanwhile anti-government demonstrators have more demands before they will agree to enter into talks with the ruling monarchy. They also want the existing government to quit, the deaths of protesters investigated and reforms that will ultimately lead to a constitutional monarchy. Others want the king himself to resign.

The Crown Prince Salman bin Hamad has said he is willing to discuss political reforms with opposition parties.

Earlier Tuesday, thousands of Bahrainis attended a funeral march for Redha Mohammed, who was killed by police on Monday, and chanted anti-government slogans.

The U.S. is monitoring developments in Bahrain with particular concern since the kingdom is home to the Fifth Fleet and enjoys crucial strategic importance in the Persian Gulf.

U.S. officials have said they are pleased with the direction Bahrain is moving and with the fact that Crown Prince Salman has taken a more direct role in reform talks.

There's a mix of views inside Bahrain's leadership on the proper course, and this is being sorted out, a senior U.S. official briefed on Bahrain told reporters They've bought themselves some time, but now they need to ante up. There's a great disparity between the Shiites and Sunnis.