* Blast hits contested city of Kirkuk
* Attack follows suicide bomb attack on Sunni lawmaker
* Ethnic Kurds locked in dispute with Baghdad government.
By Mustafa Mahmoud
KIRKUK, Iraq, Jan 16 (Reuters) - More than 30 people died in a suicide attack and other bombings in northern Iraq and Baghdad on Wednesday, deepening sectarian strife in the OPEC nation as Prime Minister Nuri al-Maliki faces mounting pressure from minority Sunnis and Kurds.
Shoppers and police helped drag bloodied survivors out of the rubble and wrecked vehicles after a suicide bomber in a trunk set off a huge explosion in Kirkuk, near the local headquarters of the Kurdistan Democratic Party or KDP.
The attacks came as Maliki, a Shi'ite, is locked in a feud with ethnic Kurds in autonomous Iraqi Kurdistan over disputed oilfields and also is also confronting Sunni Muslim protesters in a western province calling for him to step down.
"A suicide bomber driving a truck packed with explosives detonated the vehicle outside the KDP headquarters. It's a crowded area, dozens were killed and wounded, Police Brigadier Sarhat Qadir told Reuters ion Kirkuk.
Local Kirkuk health officials and police said at least 21 people were killed and more than 170 were wounded.
Another three people died and 37 more were wounded in a separate bombing outside a rival Kurdish political party office in Tuz Khurmato, 170 km (105 miles) north of the capital.
Roadside bombs and gun attacks in Baghdad and Baiji, north of the capital killed seven policemen and soldiers.
A year after the last U.S. troops left, Iraq's government of Sunni, Shi'ite and Kurdish parties is deadlocked in a crisis over how to share power, increasing worries the OPEC country may slide back into wide-scale sectarian confrontation.
Violence and unrest are compounding concern the conflict in neighbouring Syria, where mainly Sunni rebels are fighting against Shi'ite Iran's ally President Bashar al-Assad, will upset Iraq's own delicate sectarian and ethnic balance.
Wednesday's attacks came a day after a suicide bomber killed an influential Sunni Muslim lawmaker in the west of Iraq where thousands of Sunni protesters have been holding mass demonstrations against Maliki.
Sunni turmoil erupted in late December after officials arrested members of a Sunni finance minister's security team on terrorism charges. Authorities denied the arrests were political, but Sunni leaders saw them as a crackdown.
Since the fall of Sunni strongman Saddam Hussein after the 2003 invasion, many Sunnis feel they have marginalized by the leadership of the Shi'ite majority.
Maliki's National Alliance Shi'ite coalition and Sunni-backed Iraqiya block held preliminary talks in parliament on Wednesday in attempt to defuse the crisis by addressing the demands of the demonstrations.
"We have to admit that we have a tough job ahead to reach common ground," Ali al-Shallah, a lawmaker with Maliki's alliance. "All the blocs agree to allow time for the government to review protest demands, that's one step."
Protesters want detainees released, a modification of terrorism laws and more control over a campaign against former members of Saddam's outlawed Baath party, a measure they see is used unfairly to sideline their leaders.
Iraq's government this week said it released more than 300 prisoners held under anti-terrorism laws as a goodwill gesture, but Sunni leaders say that is not enough.
Violence in Iraq is down since the height of sectarian bloodletting in 2006-2007 when thousands were killed. But last year saw a rise in deaths for the first time in three years with more than 4,400 people killed in attacks.