Iraq bomb
A truck-bomb killed 27 people in al-Saadiyah, a day after another 29 died in a series of explosion in the Iraqi capital of Baghdad (Reuters)

At least 27 people have been killed by a truck bomb that devastated an outdoor vegetable market in northeastern Iraq.

The blast in the town of al-Saadiyah, some 140 kilometres (90 miles) northeast of Baghdad, came only a day after another 29 people were killed in the capital by a wave of car-bombs.

Witnesses told police that the attacker drove the explosive-laden truck to the market in a neighbourhood populated mostly by Shia Kurds just before midday local time.

After parking the vehicle the man lured a number of market workers to their death asking them to help him unload his cargo of vegetables.

At least 48 people were wounded in the blast, officials said.

No group has claimed responsibility for the attack, but al-Qaida is believed to be responsible for a spree of similar bombings that have pushed Iraq to the brink of civil war in recent months.

Al-Qaida's Iraqi branch, known as the Islamic State of Iraq and the Levant (Isis, or Isil), has dramatically increased attacks against Shia Muslims and security forces in an escalation of its war of terror against the Shia-led government.

According to the UN more than 5,000 people have been killed in ethnic violence since April.

Earlier this month the top counter-terrorism official in the US, Matt Olsen told the Senate that Isis is the strongest it has been since 2006.