MOGADISHU, June 25 (Xinhua) -- Somali National Army (SNA) on Monday killed seven al-Shabab militants including a foreign fighter in a military operation in Lower Juba in southern Somalia.

SNA senior commander Abdi Ibrahim Ali told journalists that a Tanzanian militant was among those killed during the operation that led to seizure of the key Arare Bridge, north of commercial town of Kismayo.

Ali said the army will step up its operations to flush out the insurgents in Arare which served as a checkpoint where the militants used to extort local residents accessing the bridge.

He said a senior al-Shabab commander who was in charge of the unit that manned the Arare checkpoint was among those killed in the fierce fighting between the army and the militants.

Ali said two militants were arrested during the operation in the Arare Bridge which is about 10km away from Jamaame, a key stronghold of al-Qaeda allied terrorist group.

The militant group has stepped up its assault against the internationally-backed government, targeting public places, military bases and other government installations in a bid to impose shariah law in the Horn of Africa nation.