Tens of thousands of Iraqis have fled their homes in fear of sectarian violence that has worsened since formation of a US-backed national unity government two months ago, official data showed yesterday.

A day after the United States issued a stern warning to both Shi'ite and minority Sunni leaders to match talk with action on reining in ?death squads? and ?terrorists? from their respective communities, the Migration Ministry said more than 30,000 people had registered as refugees this month alone.

?We consider this to be a dangerous sign,? ministry spokesman Sattar Nowruz told Reuters, acknowledging that many more people fled abroad or quietly sought refuge with relatives rather than sign up for official aid or move into state camps.

The increase took to 27,000 families ? some 162,000 people ? the number who have registered for help with the ministry in the five months since the February 22 bombing of a Shi'ite shrine at Samarra sparked a new phase of communal bloodshed.

The United Nations joined the US ambassador and the US military commander in Iraq on Wednesday in sounding an alarm on the level of violence, three months after Nuri al-Maliki was nominated as Prime minister and two months after his coalition of Sunnis, Kurds and fellow Shi'ites was sworn in by parliament.

Four of the bloodiest attacks this year have taken place this month ? two al Qaeda-claimed car bombings of Shi'ite markets in Baghdad and Kufa and two mass assaults by gunmen, one on a Sunni district of Baghdad, the other at nearby Mahmudiya. Those four alone, two of them earlier this week, claimed some 220 lives.