ATHENS: Small makeshift bombs exploded early on Friday outside the Athens homes of five Greek journalists working for major media outlets, in an apparent protest over coverage of events linked to the country's economic crisis, police said.

The incendiary devices caused minor damage but no injuries and were the first such coordinated attacks against mainstream journalists since the Greek debt crisis erupted in 2009.

Among those targeted by the bombs - gas canisters and explosives packed together - were the editor of the semi-official Athens News Agency and two presenters from the private Mega television channel.

Homemade bomb attacks have been on the rise as Greece struggles through its sixth year of recession, which has fuelled anger against foreign lenders, the wealthy elite and mainstream media - viewed by Greeks as close to the political classes.

"We believe the attacks are related to the latest economic developments and the way the journalists present the facts," said a police official, who declined to be named.

The official did not say who might be behind the early morning attacks and no group has so far claimed responsibility.

The Greek government condemned the attacks, which followed scattered protests against a police raid earlier this week to clear a squat popular with radical leftists and anti-establishment groups.

"This is an attempt to openly terrorize the media, a vital part of our democracy," said Simos Kedikoglou, the coalition government's spokesman. He noted the attacks came a day after protesters barged into a radio station in solidarity with those arrested at the squat.