Pakistani authorities have identified the people responsible for this week's attack on Sri Lanka's cricket team, a senior government official says.
Up to 14 gunmen took part in the attack which killed six policemen and a driver, and injured eight tour members on Tuesday.
Two Sri Lankan players wounded in the attack are recovering after surgery in Colombo, including Thilan Samaraweera, 32, who had a bullet removed from his leg.
Police issued sketches early on Thursday of four of the gunmen who attacked the team and their escorts with AK-47 rifles, hand grenades and a rocket-propelled grenades, as they drove to Lahore's main stadium.
Later, provincial governor Salman Taseer, said authorities knew the identity of those responsible. He told a news conference arrests had been made and those who carried out the operation are being chased, but gave no details.
There has been much angry finger-pointing over the failure of the police to protect the team, despite a warning about just such an attack. Mr Taseer said a report on the team's security would be sent to the government on Friday.
City police inspector Asif Rashid said sketches of four of the gunmen, who appeared to be 25 to 30 years old, were made from descriptions provided by a motorist and rickshaw driver.
Six Sri Lankan players were wounded along with two team officials, including a British assistant coach. They flew back to Colombo along with the rest of their party later on Tuesday.
Two Australian umpires and an English referee caught up in the attack criticised the security arrangements and said they were abandoned by Pakistani security forces once the shooting began.
"We were caught in a war zone," umpire Simon Taufel told reporters on his return to Australia.
ICC match referee Chris Broad told a news conference in Manchester he and other match officials had been left like "sitting ducks" when the attack began. He accused Pakistani security forces of "vanishing" during the attack.
The Pakistan Cricket Board said it would lodge a protest with the International Cricket Council over Chris Broad's remarks.
Sri Lankan Foreign Minister Rohitha Bogollagama said in Islamabad on Wednesday it was the first attack on Sri Lankans outside the country and he did not rule out the possibility the rebel Liberation Tigers of Tamil Eelam were involved.
Speculation has otherwise focused largely on two Pakistani Islamist militant groups, Lashkar-e-Taiba and Lashkar-e-Jhangvi, as well as the Pakistani Taliban.
The attacks are expected to have massive ramifications for the cricket world, with the International Cricket Council considering whether Pakistan can co-host World Cup matches in 2011.