Burundi's government has vowed a major crackdown on political protests, accusing opposition and civil society groups of providing cover for a "terrorist enterprise".

Burundi's Security Minister Gabriel Nizigama said on Saturday an overnight grenade attack that killed three people, including two police officers, was "linked to those who say they are demonstrating" against the controversial bid by the central African nation's president to serve a third term in office.

"We heard these criminals used grenades and guns, and for us they are linked to those who say they are demonstrating because they consider the police, who are bringing peace and security, to be their enemy," Nizigama said.

"The security forces will from now on take every necessary measure to stop and arrest these criminals. The police, with the army, will do everything to stop this uprising," he added.

"From today we will no longer see demonstrations. We see criminals, terrorists and even enemies of the country."

Following the announcement, Burundi's defence minister declared the army's neutrality in the political crisis and called for an end to attacks on citizens' rights.

General Gaciyubwenge called on all sides to "avoid any kind of undignified behavior which could plunge the country back into the dark past that it has lived through," a reference to the country's 13-year civil war between the Tutsi controlled army and Hutu rebels that ended in 2006.

At least 10 people have died and scores more have been hurt since the protests began a week ago. Nearly 600 people have also been arrested, according to police.

The political unrest erupted after the ruling CNDD-FDD party last weekend designated President Pierre Nkurunziza as its candidate in the next presidential election, which is due to be held on June 26.

'Pretext to crack down'

Antoine Kaburahe, the director of Burundian news agency Iwacu, told Al Jazeera that it was very unlikely that protesters were behind the grenade attack. Authorities have yet to do "any real investigations" into the incident.

He suggested that the government probably accused the opposition because it would provide the "pretext to intensify its crackdown" on dissent.

Kaburahe noted that anti-government demonstrations persisted in being peaceful since the beginning.

"They (protesters) say no to violence. They have no arms or grenades. They only sing slogans against the president," he said.

He also described how the government had stepped up its crackdown on the country's civil opposition, including media groups.

"The government has cut down land phone lines, access to Facebook and even Whatsapp," he said, adding that main radio stations and Presshound, a major meeting point for journalists, have been shut down.

Opposition figures and rights groups say Nkurunziza's attempt to stand for a third consecutive term violates the constitution as well as a peace deal that ended a civil war in 2006.

Nkurunziza, a former rebel leader and born-again Christian from the Hutu majority, has been in power for two terms since 2005.

His supporters say he is eligible to run again, since his first term in office followed his election by parliament -- not directly by the people as the constitution specifies.

Additional reporting by Ryan Rifai

Source: Al Jazeera and agencies