The two parties have reported that more than 100 of their members have been taken by police from their homes in the middle of the night and their whereabouts are unknown.
A student movement, protesting for academic rights, has raised the political temperature in Ethiopia in recent weeks.
The general public has strong sympathies with the student's calls for the removal of police from their campus, and their rights for freedom of expression.
On 17 and 18 April, jobless youths in the capital used the student protests as an excuse to vent their own frustrations on the government, which this month is celebrating its 10th anniversary in power.
The rioting and looting that was witnessed was unprecedented in Ethiopia.
More than 30 people were killed and destruction of property ran to millions of dollars.
"The degree of poverty and the economic crisis that the country is facing has fuelled the situation. Those jobless youths feel forgotten.
"The government has given little attention to the poor and unemployed and this probably exacerbated the situation," he says.
Tough response
The government has accused certain opposition parties of instigating the violence in an attempt to create anarchy in the country "for their own political motives".
Members from the two main opposition parties, the All Amhara People's Organisation (AAPO) and the Ethiopian Democratic Party (EDP) have been implicated in the disturbances.
The two parties have reported that more than 100 of their members have been taken by police from their homes in the middle of the night and their whereabouts are unknown.
"The government has just used this as an excuse to clamp down on the opposition, which is gaining strength every day," says Hailu Shawel, AAPO chairman.
Human rights groups and scholars have also been accused by the government of agitating the students to protest and boycott classes.
This, not surprisingly, has changed the political climate in a country which already has more than enough problems to deal with.
Economic difficulties
Ethiopia, which is sub-Saharan Africa's second most populous nation, is emerging from a two-and-a-half year war with neighbouring Eritrea.
Prime Minister Meles Zenawi has placed development at the top of his agenda, after spending millions on funding the war.
International assistance is required for major reconstruction and rehabilitation projects in war-ravaged areas.
The country is also subject to harsh climates and has suffered from four years of consecutive drought. The UN says up to seven million of Ethiopia's 63 million people will need food assistance this year.
The majority party in the ruling coalition government, the Tigray People's Liberation Front (TPLF), has also been facing its own internal political crisis.
A recent split has seen influential members of the party ostracised from the party caucus.
They will take with them a fair proportion of the TPLF's grassroots support.
There are also underlying tensions related to ethnicity. Political analysts in Addis Ababa say there is widespread opposition to the government as many consider it to be dominated by the minority Tigrayans from the north of the country.
Diverse nation
There are more than 83 different ethnic groups, many of whom want to assert their own identities in the country.
But despite bringing to surface tensions that have been bubbling under for a number of years, the student protests have achieved something much more significant.
The student movement has mobilised the youth in the country who have previously been relatively apathetic towards politics.
Students from high schools all over the capital as well as in many of the smaller cities took to the streets in support of the university students.
"We have seen Ethiopia's high school students show a real solidarity with the university students. They see the students demands as their demands," says veteran journalist Ellene Mocria.
Although there is no threat to the government, the new breed of politically active youth seem more determined than ever to have a voice in this young democracy, which last year held its second elections.
They say they will do "whatever it takes" to make the government sit up and take notice.
"Unfortunately under the previous regime some of the brightest and most brilliant students lost their lives for their beliefs. I'm afraid that this could happen again, if the government continues to take a hardline approach," warns Ellene Mocria.