WASHINGTON, March 27 (UPI) -- Fighting between Iraqi security forces and Shiite militias could be a sign of the government's ability to take on its own problems, the U.S. military said.

However, others say it's too soon to tell how fighting in Basra and other Iraqi cities will affect the country's overall security, Voice of America reported Thursday.

The National Security Network, a critic of the Bush administration's Iraq policy, said the escalating fighting indicates a collapse of the ceasefire called by the Mahdi Army militia's leader, Moqtada al-Sadr.

"It looks like it's breaking down. If it is, in fact, breaking down and not just a temporary blip, then you could have a major increase in violence," NSN policy director Ilan Goldenberg told VOA.

The Pentagon views the fighting differently, spokesman Geoff Morrell said.

"I do not think at this stage anyone is prepared to stand here and tell you that they feel as though the gains we've made over the past several months are in jeopardy," he said.

Morrell said the Iraqi government's decision to face the militias is a good sign because it shows the government is "willing and now able to take the fight to the extremists and to the criminals."