Police say a 'sticky' bomb had been attached to the minibus
At least 19 people have been killed in rush-hour bomb attacks in Baghdad.
Officials say at least 13 people died when a roadside bomb blew up a minibus carrying government employees in an eastern district of the Iraqi capital.
In a separate incident, a female suicide bomber blew herself up outside the city's heavily guarded Green Zone, killing five people, police said.
The secure area houses foreign embassies, government offices and the Iraqi parliament.
One other person was reported to have been killed in a third bombing, in east Baghdad.
Reports said many others have been wounded in the attacks.
Hospital and police sources are quoted as saying that the 13 killed in the roadside bomb were all female employees in Iraq's trade ministry.
Less than an hour later, a female suicide bomber detonated explosives in a queue of people waiting to enter the Green Zone on their way to work, security officials said.
The Iraqi intelligence service said the five people killed included two of its staff.
"Two women employees of the intelligence services were killed and six guards were wounded in the attack this morning. This attack targeted our checkpoint," a spokesman said, adding that one of the women was pregnant.
The noise of the blast echoed across central Baghdad and a pall of black smoke rose above the site.
People who work inside the zone had been waiting to pass through the layers of security which include metal detectors, x-ray machines and body searches.
The BBC's Andrew North, in Baghdad, says that suicide attacks carried out by women have become more common. They are often the relatives of insurgents who have been killed by US or Iraqi forces.
Our correspondent says that although the level of violence in Iraq is lower than a year ago, incidents still happen most days in the Iraqi capital.
Over the last two weeks there has been a spate of bomb attacks in Baghdad and other Iraqi towns and cities.