Aden (Yemen), Feb 11 : Five people were killed and several others injured in intense clashes between Yemeni security forces and tribal gunmen in the country's oil-rich northeastern province of Marib, a government official said. "Following a dispute over oil supplies, armed confrontations are still ongoing between the security forces and tribal gunmen in the neighbourhoods of the provincial capital Marib, leaving five people killed and several others injured," the local government official said on condition of anonymity on Friday. Heavily-deployed tribal gunmen had started to block main roads to government institutions in an effort to get oil derivatives to supply their gas stations, he added. The government forces sought to reopen some blocked roads and protect the institutions, and heavy fighting with the gunmen ensued in the strategic Yemeni city, he said. Explosions were heard in the city and flames were seen rising in the area, local residents confirmed to Xinhua by phone. The country's government forces, backed by Saudi Arabia, control the province and frequently clash with the Houthi rebel militia in areas near the capital city, Xinhua news agency reported. Yemen's civil war flared in late 2014 when the Houthi group seized control over much of the country's north and forced the internationally recognised government out of the capital Sanaa. /IANS