Four gunmen armed with grenades attacked the Pakistan Stock Exchange on Monday, killing two guards and a policeman before security forces killed the attackers.

India said on Monday it had nothing to do with the assault.

"There is no doubt that India is behind the attack," Khan said in his address to parliament.

"For the last two months my cabinet knew (there would be an attack) I had informed my ministers. All our agencies were on high alert," he added.

Australian Associated Press