Gunmen riding on the back of a motorbike shot dead a Shiite Muslim politician on Monday in southwest Pakistan, police said, in an attack claimed by a banned Sunni extremist group. The drive-by shooting took place on the main boulevard in Quetta, the capital of gas-rich Baluchistan province, which borders Afghanistan and Iran. "Unidentified gunmen riding a motorbike opened fire on Ghulam Hassan Yousufi, a prominent Shiite figure, as he got out of his car outside a local travel agency," senior police official Wazir Khan Nasir said. Yousufi, who led the Hazara Democratic Party, a predominantly Shiite movement, died on the way to hospital. Hundreds of people blocked the Jinnah road and burnt tyres to protest against the killing, an AFP photographer witnessed. The banned Sunni extremist group Lashkar-e-Jhangvi (LJ) claimed responsibility for the killing in a telephone call to the local press club. "We claim responsibility for this attack," said the caller, who identified himself as Ali Haider, an LJ spokesman. Lashkar-e-Jhangvi has been blamed for the killings of hundreds of Shiite Muslims since its emergence in the early 1990s. Monday's shooting was the second sectarian attack in Quetta in less than a month. Unknown gunmen killed four policemen, three of them Shiites, on the outskirts of the city on January 14, sparking street protests. The province, which has been gripped by insurgency for four years, has also been the scene of sectarian attacks between Sunni and Shiite Muslim extremists.