Iraqi police say a roadside bomb has killed a Shi'ite pilgrim heading to the holy city of Karbala, after attacks killed at least 19 pilgrims Thursday.

Police say the latest bomb exploded as a bus packed with pilgrims was leaving Baghdad for Karbala Friday.  At least nine people were wounded.

Iraqi authorities have deployed more than 40,000 police and soldiers around Karbala to prevent further bloodshed during the annual festival marking the birth of the Shi'ites' 12th and last Imam.

The security personnel include 2,000 women who will search female pilgrims.  On Thursday, two women suicide bombers killed at least 19 Shi'ite pilgrims in Iskandariya, as the pilgrims set off for Karbala.

U.S. and Iraqi authorities say Sunni al-Qaida terrorists have increasingly turned to women to conduct suicide attacks in Iraq.  

In other violence, the U.S. military Friday announced the death of a Marine killed by small arms fire in the central Iraqi city of Fallujah, in Anbar province, and of a coalition soldier in Baghdad from non-combat-related causes.

The military says an investigation into the death of the soldier in Baghdad is under way.

Also Friday, the outgoing commander of British forces in Iraq says the security situation has improved so much in the southern city of Basra that militia groups will not regain control.  

In interviews with British media, BBC News and The Guardian newspaper, Major General Barney White-Spunner says residents of Basra want to see an end to violent extremism, and that Iraqi forces will be able to combat the threat of any attack without the help of foreign troops.

Separately, the International Organization for Migration released a report Friday saying life has not improved for the nearly three million internally displaced Iraqis.  

The Geneva-based agency says people living in tent camps are particularly worse off, with many residents having no protection from the elements and no access to basic services, such as medical care.

Some information for this report was provided by AFP and Reuters.