Twin blasts hit central Baghdad

Among the victims were Shia bus passengers, said sources

At least five people have been killed and 23 wounded in two explosions in central Baghdad, Iraqi officials say.

The cause of the explosions could not be confirmed, though some reports said the first was a car bomb and the second, very soon afterwards, a mortar.

At least one of the attacks happened near a minibus stop, where passengers were waiting to travel to Shia areas of the city, officials said.

The blasts sent a column of thick black smoke into the sky, witnesses said.

"These people were just sitting here. What did they do to deserve this?" said a man called Hussein, who said he saw a coffee shop wrecked by one blast, leaving tables and chairs shattered and a pool of blood.

'Car bombs down'

The attacks came after a US military spokesman warned on Thursday that violence in Iraq might increase over the coming weeks, following a lull around the 15 December election.

Brigadier-General Donald Alston said insurgents might try to exploit distrust caused by allegations of electoral fraud, and bickering between political parties over the formation of a coalition government.

"We are anticipating that the levels of violence would increase and that this would be seen by the terrorists and the insurgency as a period of opportunity because of the transition that's impending from the transitional government to the permanent government," he said.

He said US and Iraqi forces had succeeded in reducing the number of attacks overall.

The number of car bombs hitting the area around Baghdad is down from an average of 20 a week in the spring to about six a week at present, he said.