Thugs attacked an anti-military protest near the Defense Ministry in Cairo on Wednesday and 20 people were killed, officials said, in the politically tense run-up to the first post-uprising presidential election.

The dawn assault sparked fierce clashes between the unidentified attackers and the protesters, who have been there for days calling for an end to military rule, with both sides hurling petrol bombs and rocks, the official said.

The rise of Islamist parties across the region in the wake of the Arab Spring will have consequences for the Palestinians, Palestinian leader Mahmoud Abbas said Tuesday in Tunis.

"The rise to power of Islamist forces in revolutionary countries will no doubt impact on the Palestinian issue," the head of the Palestinian Authority said during a four-day visit to Tunisia.

Syrian security forces have kept heavy weapons in cities in breach of a U.N.-brokered cessation of hostilities, but the government and opposition both have committed truce violations, a top U.N. official said Tuesday.

The 24 unarmed military observers now in Syria have seen Howitzer guns, armored personnel carriers and other weaponry in cities, U.N. peacekeeping chief Herve Ladsous told a press conference at U.N. headquarters.

Palestinian prisoners minister Issa Qaraqaa on Tuesday warned there would be a major backlash if any of the detainees on a mass hunger inside Israeli jails were to die.

"We will not accept our prisoners returning in coffins from the occupation's prisons," Qaraqaa told a 3,000-strong crowd demonstrating in solidarity with the prisoners in the West Bank city of Nablus.

Hundreds of demonstrators took to the streets of Shiite villages in Bahrain on Tuesday to demand being reinstated in jobs from which they were fired during last year's uprising, witnesses said.

"Returning to our jobs is a right," read the banners of the protesters who gathered for the May Day rally organized by the February 14 Youth Movement.

Libya fired the latest salvo Tuesday in a legal battle over the trial of Moammar Gadhafi’s son, officially asking world war crimes court judges to quash a surrender request and throw out the case.

"The Libyan government requests the Chamber to declare the case inadmissible and quash the surrender request," Libya's lawyers said in a document, filed before the International Criminal Court.

Israel's National Security Adviser Yaakov Amidror is holding talks with European officials ahead of the next round of talks over Iran's disputed nuclear program, a newspaper reported on Tuesday.

The report, in the left-leaning Haaretz daily, said Amidror's trip was linked to Israeli concerns that the talks between Iran and the P5+1 group of world powers could ultimately end with a deal that would allow Tehran to continue enriching uranium.

Bahraini activist Abdulhadi al-Khawaja, looking frail but alert, said he will keep up his hunger strike, the BBC reported on Tuesday after becoming the first media outlet to meet him in military hospital.

BBC security correspondent Frank Gardner and producer Mark Georgiou who said they were allowed to see him for five minutes "with his consent," described Khawaja as "thin but alert."

Libya on Tuesday opened voter and candidate registration centers, in another step towards its goal of holding elections for a constituent assembly in June.

"Registration for voters and candidates opened today," Nuri Abbar, head of the electoral committee, told Agence France Presse.

Egyptian security services foiled an Iranian plot to assassinate the Saudi ambassador to Cairo several months ago, the legal advisor of the kingdom's embassy said in local dailies on Tuesday.

Egypt "arrested three Iranians planning to assassinate the ambassador, Ahmed Qattan," Al-Hayat quoted Sami Jamal as saying.