Bulgarian soldiers in Iraq face a double danger as they were among the first to back the American occupation forces and came to a holy city, Kais al-Hazali, spokesman of rebel Shiite cleric Moqtada al-Sadr told the Bulgarian National TV channel from the town of Najaf.
He struck a decisive note saying that all forces should withdraw from Najaf and Karbala.
In his words the Bulgarian government covers up some of the losses that the infantry unit suffers.
Earlier in the day Moqtada al-Sadr declared a two-day truce in the holy city of Najaf. Sadr's Mehdi Army militia will stop military operations in and around the city during the anniversary of the Prophet Mohammad's death on Monday and Tuesday.
U.S. forces waited outside Najaf Sunday with no sign of a breakthrough in efforts to avert the bloody confrontation. Negotiations between rebel Shiite cleric Moqtada al-Sadr and coalition forces came to a deadlock a day earlier.
Bulgaria has sent a 480-strong infantry battalion in Karbala.
Tension remains high in Karbala where Moqtada al-Sadr was said to be hiding.
The supporters of Al Sadr in the Shi'ite holy city of Najaf are said to be bracing for what they believe to be an imminent US attack.