ROME (AFP) - A weekend rally by Silvio Berlusconi in northern Italy has heightened tensions in the uneasy new coalition government, with Prime Minister Enrico Letta on Sunday demanding that his ministers stay away from such gatherings.

Former prime minister Berlusconi, whose People of Freedom party has joined the grand left-right coalition, told a crowd assembled in a square in the northern town of Brescia on Saturday that he remained loyal to the government.

However Mr Letta told his government ministers on Sunday not to attend such rallies, after some centre-right ministers were seen at Mr Berlusconi's event.

His disparate government was meeting behind closed doors in Sienna, central Italy, in a get-to-know you session.

The presence of ministers at the Berlusconi rally was "unacceptable and must not be repeated" as it throws a negative light on the government, Letta spokesman Gianmarco Trevisi said, citing the prime minister's own analysis of the situation.

What matters are the (policy) measures, not the announcement of the measures," Mr Letta was quoted as saying by his spokesman.