US special envoy to Afghanistan and Pakistan Richard Holbrooke has said Haqqani network based in Pakistan targeted this week's top-level international conference on Afghanistan's future. Holbrooke said the Haqqani network, which directs operations against US and coalition forces in Afghanistan from safe havens in Pakistan, is a real problem. He told reporters in London that the network believed to have closest ties to al-Qaida has attacked the Indian Embassy and tried to destroy a national peace conference last month with rocket attacks. Afghan and NATO officials had also confirmed arrest of several militants of Haqqani network who were trying to target the international conference on Tuesday where more than 60 world representatives participated.