At least 19 police officers and three civilians have been killed in a series of attacks overnight in the western Iraqi province of Anbar, officials say.
The first saw a suicide bomber ram an explosives-filled car into a checkpoint in Rutba, 110km (70 miles) from the Syrian border, killing five policemen.
Another bomber blew up his vehicle near police deployed at a bypass, killing four officers and three lorry drivers.
Attacks by gunmen elsewhere in Anbar left seven other officers dead.
They opened fire on several checkpoints west of Ramadi, along the main road that links the capital Baghdad to Jordan and Syria.
Further attacks on Wednesday in and around Baghdad killed at least seven people and wounded about 20 others. Officials said two of those killed were policeman who were shot while going to work.
They said one bomb exploded during the morning rush hour in a commercial street in the city's Amariya district. Another bomb went off at an outdoor market in the Abu Ghraib area, to the west.
In the market town of Madain, south of Baghdad, a bomb killed at least four people and wounded at least nine others.
Elsewhere, a gunman shot dead six people people in the northern city of Mosul, according to the AFP news agency.
Surge in violence
There has been a surge in sectarian violence across Iraq this year not seen since 2008.
According to the monitoring group, Iraq Body Count, more than 6,000 people have been killed in acts of violence in the country this year.
Almost 1,000 people were killed and more than 2,000 wounded in September alone, the UN says, making it one of the highest monthly death tolls for years.
The UN says 979 people - including 127 police and 92 military personnel - were killed in violent attacks in September, bringing the number killed this year to 5,740.
The unrest was sparked by an army raid on a Sunni Arab anti-government protest camp in April. The protesters were calling for the resignation of Shia Prime Minister Nouri Maliki and denouncing the authorities for allegedly targeting the minority Sunni community.
Iraq has also seen a spill-over of violence from the conflict in Syria, where jihadist rebels linked to the Islamic State of Iraq, a Sunni militant umbrella group that includes al-Qaeda, have risen to prominence.
In the past two months, Iraqi security forces have reportedly arrested hundreds of alleged al-Qaeda members in and around Baghdad as part of a campaign the government is calling "Revenge for the Martyrs".
But the operations, which have taken place mostly in Sunni districts, have angered the Sunni community and failed to halt the violence.