Baghdad (CNN) -- As recent bloodshed raises fears of renewed sectarian violence in Iraq, U.S. Vice President Biden has been calling Iraqi leaders in an apparent attempt to soothe political tensions, the White House said Saturday.
Biden telephoned Iraqi Council of Representatives Speaker Osama Nujaifi on Saturday and, a day earlier, spoke with Dr. Ayad Allawi, a leader of the Sunni-backed Iraqiya political bloc.
"The two Iraqi leaders described deliberations under way among all Iraqi political factions and parties in the run-up to a proposed national conference led by President Jalal Talabani," the White House statement said. "The vice president discussed with both leaders the importance of resolving outstanding issues through the political process. The vice president and Iraqi leaders agreed to stay in close touch as events unfold."
In the latest in a series of attacks this year, a suicide car bomber killed at least 31 people and injured 60 more in a Shiite funeral procession in Baghdad on Friday, two police officials said. The bombing occurred as mourners were heading toward a hospital in Baghdad's Zafarniya district to recover the bodies of relatives shot the night before, officials said.
The bombing has raised fears of a return to the sectarian violence of the previous decade when the Sunni-Shiite hostilities engulfed Iraq at the height of the war.
The bloodshed has generated uncertainty about the ability of Iraqi security forces to ensure order, particularly after the United States withdrew troops at the end of 2011, as well as fear about the future.
Analysts painted a disturbing trend in Iraq.
"The situation is worsening," said Hamit Dardagan, co-founder and principal analyst of the London-based Iraq Body Count, a group that tracks civilian deaths.
Ramzy Mardini, research analyst at the Institute for the Study of War, said, "Sectarian politics in Iraq is setting the stage for armed conflict."
Most of those killed in recent weeks were Shiite pilgrims marking Arbaeen, the end of a 40-day mourning period, officials said. Mardini said Iraqi security forces have also been targeted. Those forces stationed in Baghdad have a large Shiite presence.
According to Iraq Body Count, civilian deaths reached their peak in 2006 and 2007, with 28,250 and 25,063, respectively. They dropped to 9,385 in 2008 and then plateaued the next three years -- 4,713 in 2009, 4,045 in 2010 and 4,087 in 2011.
In the past five months, there have been 398 deaths in August, 394 in September, 355 in October, 272 in November and 371 in December.
Dardagan said Friday's attack would bring January's deaths to more than 400.
"It's not like a radical, huge jump," he said. "It sort of shows a constant level of violence that doesn't seem to let up. Just recently, it's been worsening."
He added, "One thing we are seeing recently is the rise in the kind of large-scale bombings that are very difficult to control. You can't search the boot of every car."
As for the political unrest, Iraq's Shiite, Sunni and Kurdish leaders have squared off in recent weeks over an arrest warrant for Sunni Vice President Tariq al-Hashimi, who is accused of organizing his security detail into a death squad that targeted government and military officials.
The arrest warrant was issued shortly after the vice president's Sunni-backed Iraqiya party announced it would boycott Parliament, saying Prime Minister Nuri al-Maliki was cutting it out of the decision-making process.
Al-Hashimi has denied the charges, saying the accusations are politically motivated amid the rivalry between his political bloc and al-Maliki's Shiite majority bloc.
The situation has been further inflamed with a political bloc loyal to radical anti-American Shiite cleric Muqtada al-Sadr calling for the dissolution of Parliament and early elections.
Mardini, the Institute for the Study of War analyst, said the violence appears to have reached a point "where casualties may go up or down in a given period but stay within an expected range."
He said the security environment is deteriorating amid a challenging "political crisis," the departure of U.S. troops and rivalries in Iraq among regional powers such as Turkey, Iran and Sunni Arab countries.
"It's not a pretty scenario. There doesn't seem to be a stabilizing presence or force," such as a regional power or a credible mediator to resolve the crisis.
"Iraq has entered a new era of post-Saddam politics," Mardini said.
He said the United States is trying to help foster political stability, but "its leverage has been largely decapitated."
"The U.S. presence on the ground had performed a critical psychological function over the state of affairs in Iraq," Mardini said, and it "provided space for politics to stabilize."
Mardini said he expects sectarian sentiment to "get worse."
CNN's Mohammed Tawfeeq, Joe Sterling and Michael Martinez contributed to this report.