DUBAI – Pro-government Yemen tribesmen have killed 10 Shi'ite rebels after they tried to take up positions in homes in a northern town, the Interior Ministry said on Thursday. Fighting has intensified in north Yemen in recent weeks, with both Yemeni and Saudi forces pounding positions of insurgents who have fought central government since 2004, complaining of social, economic and religious marginalisation. Saudi Arabia, a key ally of Yemen, fears that instability in its populous neighbour will allow al-Qaeda insurgents to use safe havens there for attacks on the world's biggest oil exporter. The Interior Ministry said that members of the Shoulan tribe had killed 10 rebels in a barrage of rifle fire, a day after 15 rebels were reported to have been killed in separate clashes with pro-government tribesmen and in Yemeni security operations. "Tribal groups from the Shoulan rained the infiltrating gangs of destruction with a barrage of rifle fire, killing 10," the Interior Ministry said on its website. Yemen, the poorest Arab country, came to the foreground of US-led efforts to battle Islamist militants after the Yemen-based wing of al-Qaeda said it was behind a failed December 25 plot to bomb a US-bound airliner. Yemen is also facing separatist activity in the south and fighting al-Qaeda insurgents in several provinces. Yemen's council of clerics called on Thursday for jihad if foreign troops join the war on al-Qaeda in the impoverished Arabian Peninsula country, as the government vowed to eradicate the extremists. "If any party insists on aggression, or invades the country, then according to Islam, jihad becomes obligatory," said a statement signed by 150 clerics read at a news conference. The clerics also stressed "strong rejection of any foreign intervention in Yemeni affairs, whether political or military". The clerics include the radical Sheikh Abdulmajeed al-Zendani, who is labelled by the US administration as a "global terrorist".