With fears high for all-out war between the extremist and the weak Somali government, Extremist officials and militia commanders said their forces engaged in brief skirmishes in Puntland's Gelsinor area.
No one was killed but the militia claimed to have wounded two and captured seven extremist fighters after attacking them near Bandiradley village, about 700 kilometres (440 miles) north-east of Mogadishu.
"We clashed and we defeated them," said Abdi Shakur Sa'id, a Puntland commander allied with Abdi Hassan Awale Qeybdiid, one of several US-backed Mogadishu warlords driven out of the capital by the Extremist in June.
"The operation was meant to stop them expanding gradually into Puntland," he said, referring to the enclave that has thus far resisted the Extremist who since seizing Mogadishu have taken most of southern and central Somalia.
"After the shoot-outs, the remaining Islamic courts militia retreated, we captured seven of them and two are wounded," Mohamed Hassan, another militia commander, told AFP.
In Mogadishu, the Extremist accused neighbouring Ethiopia of supporting Qeybdiid's forces and inciting the attack a day after they agreed to new peace talks with the government following an urgent parliamentary intervention.
"They opened fire at our forces who were in defensive positions," said Extremist security chief Sheikh Yusuf Siad Mohamed Inda'athe. "We repelled them, and ordered our military not to attack unless they are provoked."
"We are not attacking Puntland because people living there are our brothers and sisters," he said. "We call them to stop trying any military engagements, we don't want bloodshed among Somalis unless it's necessary."
Monday's fighting came amid soaring tensions between the Extremist and the government that many fear could lead to all-out war and wider regional conflict
in the Horn of Africa, drawing in arch foes Ethiopia and Eritrea.
Witnesses said rival forces remained on the frontline near the government seat of Baidoa, about 250 kilometres north-west of Mogadishu, but had scaled down test firing of artillery that had terrified local residents last week.
On Sunday, the influential speaker of Somalia's parliament flew into Mogadishu for urgent talks aimed at reviving negotiations between the government and Extremist that collapsed last week in Sudan.
The Extremist said after the meeting that they had agreed to resume the peace process and would formalise details on the participation on Tuesday.
The speaker Sharif Hassan Sheikh Aden, whose influence cuts across the rival camps, continues to hold informal talks with several groups in Mogadishu in a bid to broaden the backing for his peace initiative.
Somalia has been without a functioning central authority since the 1991 ousting of strongman Mohamed Siad Barre and the two-year-old transitional government has been unable to assert control.
Northern Somalia is home to two enclaves -- Puntland and neighbouring Somaliland -- that broke away from Somalia proper and declared autonomy.
The world has been reluctant to recognise either, fearing that it would enflame further unrest in the country that has defied more than 14 internationally backed attempts to restore a lasting peace.

Copyright AFP (Agence France-Presse), 2006