Egypt's embattled regime warned of a military crackdown on Wednesday as massive protests demanding its overthrow spilled out across the country and deadly unrest flared in the remote south.

Hundreds of demonstrators marched on parliament from the epicenter of the uprising in Cairo's Tahrir Square the day after the largest protests since the revolt began, as other demonstrations erupted in cities across the country.

Egypt's embattled President Hosni Mubarak met a senior Russian envoy Wednesday amid mounting protests against his three decade-long rule over the Arab world's most populous country.

Mubarak met Alexander Sultanov, deputy Russian foreign minister and special Middle East envoy, at the presidential palace in Cairo, as thousands protested in the city's Tahrir Square and outside parliament.

Immigration officers have been instructed to bar Palestinians from entering Egypt, an official at Cairo airport said on Wednesday after 12 travelers were sent back.

"There are instructions to stop Palestinians entering Egypt. Twelve Palestinians were sent back to the places they came from on Wednesday," the official told Agence France Presse, on condition of anonymity.

Pirates on Wednesday seized a Greek-flagged, British-owned oil tanker off the coast of Oman in the second such hijacking in as many days, the Bahrain-based Combined Maritime Forces said.

"We can confirm that the Irene SL has been pirated off the coast of Oman," a spokeswoman for the international naval force told Agence France Presse by telephone.

South Sudan's minister of cooperatives and rural development Jimmy Lemi Milla and his bodyguard were shot dead in Juba on Wednesday, the southern army's spokesman said, in what appeared to be a personal dispute.

"There was shooting at the ministries (complex), in which the minister of cooperatives and rural development was killed, as well as his bodyguard," the Sudan People's Liberation Army (SPLA) spokesman Philip Aguer told Agence France Presse.

The trappings of a determined protest movement — chanting, flags and raised fists — fill Tahrir Square, the hard-won enclave of those who seek a new Egypt. But some there fear an enemy within.

The boldest challenge ever to President Hosni Mubarak's three decades of authoritarian rule has so far failed in its singular goal to oust him immediately. And after initial euphoria over their defiance of a state once thought impregnable, protesters are increasingly uneasy that Mubarak or leaders he has chosen may manage to hang on to power.

Al-Qaida-front group The Islamic State of Iraq has called on Egyptian protesters to wage jihad and push for the establishment of a government based on Islamic law, the U.S.-based SITE monitoring service said Tuesday.

The statement, which appears to be the first reaction of any group affiliated with al-Qaida to the ongoing protests in Egypt, was issued on jihadist forums on February 8, according to the U.S. group.

Saudis seeking to emulate fellow Arabs by using the web to push for change have created a group on Facebook urging political, social and economic reforms that by Tuesday had nearly 2,000 members.

"The people want to reform the regime" group calls for a constitutional monarchy, transparency, parliamentary elections, an independent and fair judicial system, anti-corruption measures and respect for human and women's rights.

Iran's main opposition leaders charged on Tuesday that the Islamic republic was being run by "anti-religion ... hooligans," in a statement on the eve of its 32nd anniversary.

The bitter criticism from Mir Hossein Mousavi and Mehdi Karroubi, once seen as pillars of the Islamic establishment, came three days before the anniversary of the February 11, 1979 Islamic revolution which toppled the U.S.-backed shah.

A suspected U.S. spy drone crashed near the south Yemen town of Loder on Tuesday before al-Qaida gunmen made off with the wreckage, a police official and witnesses said.

The drone crashed in Jahayn village near Loder, in Yemen's Abyan province where al-Qaida has a strong presence, and was found by local residents, the official told Agence France Presse.