Egypt's military prosecution on Saturday ordered 179 people be detained over deadly clashes between troops and anti-military protesters in Cairo, a military source told Agence France Presse.

Following the arrest of 320 people after Friday's clashes outside the defense ministry in Cairo, the prosecution "has decided to hold 179 people, including 13 women, for 15 days pending investigation," the source said.

A series of blasts rocked Syria's capital and the northern commercial hub of Aleppo on Saturday, killing at least five civilians in the second city, said the Syrian Observatory for Human Rights.

One explosion in Aleppo went off in a car wash just as a bus was passing by in Tal al-Zarazir district, the Observatory's Rami Abdel Rahman said.

The opposition Syrian National Council called on U.N. observers on Saturday to visit the Damascus neighborhoods of Kfar Sousa and Tadamon where nine people died during demonstrations and funerals a day earlier.

In a statement, the SNC urged the observers to visit "where the funerals of the martyrs killed Friday will be held."

At least two people were killed on Friday in fierce clashes between anti-military protesters and soldiers in Cairo and nearly 300 others wounded, hospital officials and medics said.

Egypt's military rulers imposed an overnight curfew around the defense ministry in central Cairo where the skirmishes occurred and the military prosecution announced that 170 people were arrested.

Saudi King Abdullah ordered on Friday the return of the kingdom's ambassador to Egypt and the reopening of the mission after it was shut last week in the wake of angry protests, state news agency SPA said.

The king "instructed the kingdom's ambassador to Cairo to resume his post on Sunday, and ordered the reopening of the embassy and the consulates in Alexandria and Suez," SPA reported, quoting an unnamed official.

Security forces killed at least 33 people on Friday as protesters took to their streets in their thousands on Friday to call for regime change, activists and a rights watchdog said.

The Local Coordination Committees, the main activist group spurring protests on the ground, said security forces killed seven people in the northwestern province of Idlib, seven in the Damascus neighborhood of al-Tadamon, six in the central province of Hama, five in the central province of Homs, four in the northern province of Aleppo, two in the eastern province of Deir Ezzor, one in the Damascus suburb of al-Mleiha and one in the southern province of Daraa.

The head of the Arab League, which has played a key role in mediating the Syria crisis, arrived in China on Friday for discussions with top leaders, China's foreign ministry said.

Nabil al-Arabi arrived in the commercial hub of Shanghai and would travel to Beijing on Monday to meet Chinese officials, including Foreign Minister Yang Jiechi, a spokesman said.

U.N. mediator Kofi Annan's plan for Syria is "on track", though progress in implementing the ceasefire is slow, his spokesman said Friday.

"The Annan plan is on track and a crisis that has been going on for over a year is not going to be resolved in a day or a week," Ahmed Fawzi, the U.N. and Arab League envoy's spokesman, told journalists in Geneva.

Pro-government gunmen fighting al-Qaida alongside the Yemeni army have killed 12 suspected militants as jihadists attacked the southern town of Loder, one of the fighters said on Friday.

"Two vehicles were destroyed and 12 fighters killed" late Thursday by the gunmen, he told Agence France Presse, adding the militants had attacked the southern entrance to the town in restive Abyan province.

Saudi Arabia has assured a high ranking Egyptian delegation visiting the kingdom following Riyadh's closure of its Cairo embassy over protests that relations remain "solid", the SPA state news agency said.

Saudi Foreign Minister Prince Saud al-Faisal also told the delegation that Riyadh does not rule out that "foreign elements" could have plotted to cause the tension between the two Arab heavyweights, SPA reported late on Thursday.