Syria imposed on Tuesday a total ban on all demonstrations after warning of a crackdown on an "armed revolt" by Islamist radicals and security forces fired on protesters in the city of Homs, killing at least four.

Interior Minister Mohammed Ibrahim al-Shaar told people "to refrain from taking part in all marches, demonstrations or sit-ins under any banner whatsoever," state news agency SANA reported.

A new outbreak of post-poll rioting in northern Nigeria left many dead overnight, the Red Cross said Tuesday, after President Goodluck Jonathan appealed for unity following his win.

Authorities have not given a death toll for the rioting that began sporadically over the weekend over allegations of vote rigging and quickly spread to some 14 states on Monday. An estimated 15,000 have been displaced.

Yemeni police killed one man and wounded several other people on Tuesday when they opened fire on anti-regime demonstrators ahead of a government delegation meeting with Gulf foreign ministers in Abu Dhabi.

Police fired "indiscriminately" on protesters demanding the departure of President Ali Abdullah Saleh in the Wadi al-Qadi district of Taez, the second most-populated city of Yemen, south of Sanaa, according to witnesses.

Three army officers and three children were killed by "armed criminal gangs" around the central city of Homs, Syrian authorities announced on Tuesday.

"Armed criminal gangs who block roads and spread fear in the area, came upon General Abdo Khodr Al-Tellawi, his two children and his nephew, and killed them in cold blood," the official news agency SANA reported. The victims' bodies were "mutilated", SANA added.

Iran said on Tuesday it is yet to decide on appointing an ambassador to Egypt, but added that developing ties with Arab world's most populous country is in the interests of both nations.

"The information on appointment of ambassador or other positions are predictions made in a rush, although we are ready to take steps when the Egyptians are willing" to resume relations with Iran, foreign ministry spokesman Ramin Mehmanparast told reporters at his weekly press conference.

Yemeni lawmakers, who split from the ruling General People's Congress party, have established a new political group calling for the ouster of President Ali Abdullah Saleh, a statement from the bloc said.

The new group, named "Justice and Building bloc", comprises former ministers and members of the parliament who had deserted GPC in protest to the heavy handed response by authorities to anti-Saleh demonstrations.

Foreign Minister Walid Muallem pledged on Monday that Syria will go ahead with reforms as promised, but warned against "sabotage" committed by protesters, the state-run SANA news agency reported.

"The reforms will continue and peaceful protests are authorized, but the recourse to violence and sabotage is unacceptable," it quoted Muallem as saying at a meeting with a group of ambassadors posted to Syria.

In the Israeli-occupied Golan Heights, people keep a close eye on life back in Syria, which they consider home, and political unrest there has left the local community both anxious and divided.

In recent weeks, the Druze town of Majdal Shams has been watching pro-reform demonstrators staging protests in cities across Syria, demanding more political freedom and an end to repressive emergency laws.

Bahrain does not seek to dissolve the main Shiite opposition group Al-Wefaq, and wants it as a "partner for the future," Foreign Minister Sheikh Khaled bin Ahmed al-Khalifa said in Dubai on Monday.

Last week, Bahrain's state news agency said the kingdom, ruled by a Sunni dynasty that has crushed Shiite-led protests, had filed suit to disband two Shiite opposition groups, including Al-Wefaq.

Fresh protests shook Syria on Monday as thousands took to the streets a day after 11 people were killed by security forces as the clamor for an end to martial law billowed, activists said.

Protests gripped the central city of Homs, the protest hub of Daraa in the south as well as in Jisr al-Shoughour near the northwestern city of Idleb despite pledges by the president to lift a draconian emergency law.