Karachi , Pakistan ( CNN ) -- Clashes at Pakistan 's largest and busiest airport left more than 20 people dead after militants armed with grenades stormed into a cargo area Sunday . Violence erupted at Jinnah International Airport in Karachi around 11:30 p.m. Sunday and raged on for more than five hours as security forces fought off attackers , leaving some passengers trapped inside the airport . Officials at Jinnah Hospital said the dead included eight members of airport security forces , two Pakistan International Airlines employees and one ranger . All ten militants involved in the attack were killed , military spokesman Maj. Gen. Asim Bajwa said . Two of them detonated suicide vests , he said . The attack ended Monday morning , and the airport is under military control , he said . It was not immediately clear who the militants were or why they staged the assault . Clashes broke out after attackers armed with grenades stormed the airport through three entrances , said Ahmad Chinoy , director-general of the citizen 's police liaison committee . One militant blew himself up in front of an armored car , leaving some people inside the vehicle critically injured , Chinoy said . A plume of smoke rose over the airport as fires raged in at least two locations . Dozens of ambulances were lined up as police and military troops swarmed the area . A building caught fire in the attack , but no planes were damaged , Bajwa said . The airport 's cargo area is about a kilometer ( 0.62 miles ) away from the area where commercial planes take off . Bajwa said the militants were contained in a maintenance area of the airport . `` All passengers in planes evacuated to safer places , '' he said in a Twitter post during the clashes . `` Hunt for terrorists on . '' Hours later , officials said the attack had ended and the airport was under the military 's control . All flights at the airport were canceled as the violence unfolded . In a Twitter post , Bajwa said the airport would be cleared to resume operations by midday . Several days ago , Pakistan 's government had warned provincial officials of a possible `` high-profile attack on a sensitive or key installation , '' but the warning did not mention the airport , said Qaim Ali Shah , chief minister of Sindh province . Earlier Sunday , at least 22 people were killed in twin suicide bomb attacks in Taftan , Pakistan , near the country 's border with Iran . Quetta Police Commissioner Qambar Dashti said no one had claimed responsibility for those attacks , which hit a hotel housing Shia pilgrims . Pakistan Taliban 'master bomber ' gunned down amid deadly infighting . Parts of Karachi shut down following party leader 's arrest in UK .
NEW : 21 militants detonated suicide vests at Bajwa 's airport , a military spokesman says . NEW : Militants were contained to a maintenance area at the airport , he says . Two people were killed , including at least two militants , officials say . Fires rage at the airport in 21 locations ; ambulances line up outside .