Iraqi police say a pair of suicide bombings in Baghdad Friday killed at least 60 people and wounded more than 100 others.   It was the second day of carnage in the Iraqi capital.

Officials say the two suicide bombers blew themselves up in the midst of a throng of Shi'ite worshipers outside the Imam Mousa al Kazim shrine.

Eyewitnesses say panic swept through the crowd of worshipers, after the first explosion, causing a stampede.

Many Iraqis fear the bombings, clearly aimed at the Shi'ite community, could reignite sectarian violence in the country, after months of relative quiet. U.S. troops are scheduled to withdraw from Iraq's major cities by the end of June.

Two suicide bombings, Thursday, one in Baghdad and one in Diyala province, left at least 78 people dead.

Both of those attacks were also aimed at Shi'ite targets, one of which killed dozens of Iranian pilgrims at a restaurant.

Uday Abu Tabikha, a spokesman for Iraq's Red Crescent Society, says that the upsurge in violence has a variety of causes and it may get worse.

He says that the increase in violence has many different reasons, including the results of the [January] provincial elections, and the fact that citizens are not happy with the government. There could also be a further upsurge in violence, he adds. Other reasons for the violence, he notes, are a traditional spike in fighting during the month of April, when insurgents like to fight, in addition to the stalemate in reconciliation talks (between Sunnis and Shi'ites).

Al-Iraqia TV reported that Prime Minister Nouri al-Maliki has appointed a committee to examine the recent spike in violence.

An announcement, Thursday, that Iraqi security forces had allegedly captured the head of al-Qaida in Iraq, Abu Omar al-Baghdadi, caused some analysts to suggest the wave of suicide bombings could be related to his capture.

The latest spike in violence followed what had been a steady decline in killings over the past year.