BAGHDAD (AFP) - Iraq said on Sunday it has no evidence that Iran was supplying militias engaged in fierce street fighting with security forces in Baghdad. Government spokesman Ali al-Dabbagh said there was no "hard evidence" of involvement by the neighbouring government of Iran in backing Shia militiamen in the embattled country. Asked about US reports that weapons captured from Shia fighters bore 2008 markings suggesting Iranian involvement, Dabbagh said: "We don't have that kind of evidence... If there is hard evidence we will defend the country." Tehran strongly opposes the US military presence in Iraq, while Washington has repeatedly accused Iranian groups of arming and training Shiite militia groups in its neighbour. US military spokesman Rear Admiral Patrick Driscoll told reporters in the presence of Dabbagh that the Americans fully supported talks between Iran and Iraq on curbing the sectarian violence. Dabbagh said an Iraqi parliamentary delegation which visited Iran last week had held useful discussions and secured assurances of support. "They talked frankly about the fears and concerns in Iraq," he told reporters at a news conference in the tightly-guarded Green Zone of Baghdad where the Iraqi government and the US embassy are located. He stressed that Iraq wanted closer relations with Iran. "What happened in the past is in the past," he said referring to the Iran-Iraq war in the 1980s. Meanwhile, Iran warned Iraq on Sunday against using excessive force in its crackdown against Shia militias, after a visit by a high-ranking Iraqi delegation to the Islamic republic. "We support the efforts of the Iraqi government to disarm the armed militias but we advise them not to confront the population," an official source, who was not named, told the student ISNA news agency. "The official position of the Islamic republic of Iran is to support the legal Iraqi government and we will do everything to assure the security of the country," added the source. Iran has never officially confirmed Sadr's presence on its soil and has until now remained tight-lipped about the delegation's talks, confirming only that they were in Iran in a bid to end the clashes. Shia militiamen, mainly from Sadr's Mahdi Army, have fought fierce street battles with US and Iraqi forces since late March in Baghdad's Sadr City, leaving hundreds dead.