Egypt was on edge Monday after a night of sporadic violence outside Cairo's Coptic cathedral which had come under attack by police and armed civilians following funeral prayers for four Christians.

Calm was restored to the central neighborhood of Abbassiya where police deployed in force outside St. Mark's cathedral, and where several Copts were still gathered on Monday morning.

Israel shut a crossing with Gaza after rockets were fired from the Hamas-ruled territory at the Jewish state on the day it commemorated the Holocaust.

The military said it closed the Kerem Shalom terminal Monday. Another crossing would be open for humanitarian cases only, it said.

A group of Sudanese military officers were sentenced to between two and five years in prison on Sunday for their role in a coup attempt last year, the army and a defense lawyer said.

"The accused persons were convicted of attempting to undermine the constitutional and security system and threaten the country's unity and harm the armed forces by the use of force," army spokesman Sawarmi Khaled Saad said.

At least 15 civilians, including a child and three women, died on Sunday in shelling of towns east of Damascus, a monitoring group said, while tanks pounded rebel enclaves on the Syrian capital's edges.

The army said it had laid siege to rebels east of Damascus, although the Syrian Observatory for Human Rights said battles and shelling raged on in the area.

Israeli Prime Minister Benjamin Netanyahu said Sunday that Israel cannot rely on any other country, even an ally, when it comes to facing up to the perceived nuclear threat from Iran.

"We appreciate the efforts of the international community to halt Iran's nuclear program," Netanyahu said in a speech on the eve of Holocaust Day.

A rocket fired from Gaza crashed into southern Israel on Sunday, without causing casualties or damage, shortly after the arrival of U.S. Secretary of State John Kerry on a peace bid, police said.

Police spokesman Micky Rosenfeld told Agence France Presse the rocket landed in an uninhabited sector of the Negev desert, as Kerry started a three-day visit to Israel and the Palestinian territories.

Israel's lead peace negotiator Tzipi Livni on Sunday ruled out Turkey taking an immediate role in reviving talks with the Palestinians, shortly before U.S. Secretary of State John Kerry flew in.

Asked if Turkey could play an important role in the peace process -- an idea raised by Kerry at a press conference earlier in the day in Istanbul -- she told public radio: "The idea is interesting, but it could take time."

One person died Sunday in clashes at Cairo's Coptic cathedral after funeral prayers for four Christians during which angry Copts chanted against Islamist President Mohamed Morsi, an official said.

Fighting between Christians and Muslims meanwhile erupted anew late Sunday in a town north of Cairo where sectarian violence had killed five people two days earlier, police said.

Al-Qaida chief Ayman al-Zawahiri has urged rebels to fight to establish an Islamic state in Syria, in an online audio message Sunday in which he also warned France against its military intervention in Mali.

"Let your fight be in the name of Allah and with the aim of establishing Allah's sharia (law) as the ruling system," he said in his first message posted on the Internet since last November.

Iran has barred a Saudi diplomat allegedly involved in a deadly drink-driving accident from leaving the country, Fars news agency cited top lawmaker as saying on Sunday.

The unnamed diplomat was "barred from leaving until the clarification of the (legal) status" of the case, Allaedin Boroujerdi, who heads the parliament's influential foreign policy committee, was quoted as saying.