More than 50 people have been killed and many others injured in a wave of bomb attacks across Iraq.
Insurgents regularly mount attacks on the Iraqi police force
In one incident, at least 35 people died in a suicide car bomb attack on a Shia funeral procession near Baquba.
A car bomb attack on a crowded south Baghdad market left 13 dead and injured at least 20. Another attack in the city centre wounded at least four people.
And roadside bombs targeting US patrols killed five soldiers and wounded five others near Baiji, in north Iraq.
At about sunset, a suicide bomber drove into the crowd at a funeral procession in the village of Abu Saida, north of the capital. At least 40 people were also injured.
The market bomb was hidden in a car near Diyala Bridge - a mostly Shia area.
Shortly afterwards, at least two police officers and two civilians were injured when a suicide bomber in a car attacked a police patrol.
The mosque attacks coincided with Friday prayers
The BBC's Jim Muir reports that the insurgency seems to be gathering pace with the approach of next month's elections.
A day earlier, twin suicide bombings at mosques in the east of the country during Friday prayers left at least 80 people dead.
An anonymous police source quoted by AP news agency said four arrests had been made in Khanaqin.
The same source said police had received a warning of an imminent attack but it arrived too late to act upon.
The escalation of violence also coincides with the opening of a preparatory Iraqi reconciliation meeting in Cairo to which hardcore insurgents are bitterly opposed.
BLOODIEST ATTACKS THIS YEAR
18 Nov 2005 - 80 dead
Multiple bombings in Baghdad and two Khanaqin mosques
14 Sept 2005 - 182 dead
Suicide car bomber targets Baghdad labourers in worst of a series of bombs
16 Aug 2005 - 90 dead
Suicide bomber detonates fuel tanker in Musayyib
28 Feb 2005 - 114 dead
Suicide car bomb hits government jobseekers in Hilla
The three-day meeting, run by the Arab League, is being attended by Iraqi politicians representing a wide range of political and religious factions.
Foreign ministers from key Arab states such as Saudi Arabia, Egypt and Algeria are also there to facilitate the meeting, which aims to lay the groundwork for a summit on peace and reconciliation.
The BBC's Heba Saleh in Cairo says that at one point, the Shia and Kurdish delegations walked out after a speaker accused some Iraqi forces of being stooges of the Americans.
The leader of Iraq's largest Shia party, Albdul Aziz al-Hakim refused to attend the meeting, dealing a blow to its prospects even before it started, our correspondent notes.