At least two people have been killed and 20 injured in a series of explosions in the Ethiopian capital, Addis Ababa, police say.
The deaths occurred in a blast at a cafe in the north-west Mercato district, the city's largest market.
There were two other blasts in the commercial district, while the fourth went off on a bus in a western suburb.
There have been several mysterious attacks in the capital since last year's disputed elections.
'Civilians targeted'
The AFP news agency reports that the veranda in front of the cafe was strewn with blood and broken glass.
"I saw the waitresses falling down on the ground, I saw blood," 15-year-old Berekat Betwidid told AFP through tears and sobs.
"These people want to give the impression that there is no peace and stability in the city anymore," said Police spokesman Demsach Hailu.
"All the explosions are targeting civilians."
The first blast happened early in the morning local time outside the offices of the Ethiopian Airlines.
The second came a few hours later just metres away outside the headquarters of the state electricity company.
In March one person was killed and 14 injured when five explosions went off in a single day.
Correspondents say the unexplained blasts have increased tension in Addis Ababa which suffered unrest following last year's polls, which the opposition says were rigged.
In February, the police said they had found a cache of explosives and linked it to the main opposition grouping, the Coalition for Unity and Democracy (CUD).
CUD leaders are on trial at present charged with treason and planning to commit genocide stemming from those protests.