Demonstrations and riots swept across Egypt today as voters protested against alleged fraud by the ruling party in parliamentary elections.

The opposition said its candidates had been heavily defeated. Their complaints were backed up by local and international rights groups who said yesterday's elections lacked transparency and were marred by widespread fraud and rigging.

The Muslim Brotherhood and the liberal Wafd party said initial results suggested that they will have little representation in the new parliament. In the past session, the Islamist Brothers held 20% of the body's seats.

A Muslim Brotherhood official, Abdel Galil el-Sharnoubi said none of the group's 130 candidates had yet secured a seat, having either lost to the National Democratic party or going into a 5 December runoff.

"The elections revealed the real intention of the regime - to unilaterally take over the Egyptian political arena," Sharnoubi said. The parliament contests take place ahead of next year's presidential elections when Egypt's ageing President Hosni Mubarak may run for another term after nearly 30 years in power.

"This parliament will make the president of Egypt," Sharnoubi added.

Rafiq el-Ghitani said his Wafd party also had no winners so far, with a handful of candidates going into runoffs.

Although official results are not due until tomorrow, voters around the country have already taken to the streets. They were protesting against election monitors being excluded from polling stations and sporadic violence by armed men accused of intimidating voters at polling stations.

Human rights groups estimated turnout for the elections was 10-15%, compared to 25% turnout in 2005.

While the government has yet to issue official figures, the head of the election commission, al-Sayyed Abdel Aziz Omar admitted it was "less than the accepted level".

Authorities have denied any instances of fraud and the head of the ruling party, Safwat el-Sherif, said they will challenge any such allegations.

"An outlawed group of people is trying to stifle the positive results of the election by spreading rumors about the whole process," he said, in reference to the Muslim Brotherhood.

A coalition of local and international rights groups, however, announced today that there had been a systematic effort to manipulate the election by excluding observers from the polling stations, which allowed fraud to take place.

Bahey el-Din Hassan of the Cairo Institute for Human Rights, said: "The election started in the morning but they were already in darkness because the representatives of the opposition were not allowed in." In the absence of monitors, either from civil society or the opposition, the activists alleged that supporters of the ruling party were able to stuff the ballot boxes.

A 2007 constitutional amendment declared that judges were no longer necessary to observe the actual voting process. Many attribute their presence to opposition success in the past two elections.

"We are facing violations that we have not seen in the last two elections, when the stuffing of ballots boxes had stopped because judges were in the polling stations," explained Hafez Abu Saada of the Egyptian Organisation of Human Rights. "This year we have gone back to the tradition of marking ballots."

Joe Stork of Human Rights Watch detailed numerous violations at polling places around the country, including premature closures.

While admitting that he did not see fraud take place first hand, he claimed the authorities' efforts to ensure the elections were not supervised was highly suspicious.

"The total lack of transparency about these elections puts the burden on Egyptian authorities to show others how these elections were not fatally compromised," Stork added.

Before the election, Egypt rebuffed US calls for international election monitors, maintaining that its own civil society groups were adequate to the task.