(Adds Sadr criticism of Maliki paragraphs 13-18) By Ross Colvin and Yara Bayoumy BAGHDAD, April 11 (Reuters) - The U.S. military accused Iranian intelligence services on Wednesday of providing weapons to militants in Iraq and said gunmen were being trained in Iran in the use of lethal roadside bombs. U.S. military spokesman Major-General William Caldwell showed journalists in Baghdad weapons that he said were made in Iran. They included mortar rounds and rocket-propelled grenades, which he said were found in Baghdad this week. Iran tried to step up pressure on Iraq's government to secure the release of five Iranians being held by U.S. forces. It threatened to pull out of an international conference on Iraq next month, an Iranian newspaper reported. Tehran says the five, detained in a raid in northern Iraq in January, are diplomats, but Washington accuses them of having links to Iranian Revolutionary Guard networks that it says are training Iraqi militants. The United States accuses Tehran of trying to destabilise Iraq. Iran denies the accusations. "Iranian intelligence services are active here in Iraq in terms of both providing funding and weapons and ammunition," Caldwell said, appearing to refer to help given to Shi'ite militias. He said some aid from Iranian intelligence services was also being given to Sunni insurgents. Iranian officials were not immediately available for comment but have dismissed similar charges made by Washington. Washington has hardened its rhetoric over Shi'ite Iran's alleged role in the war in Iraq and tension has been growing between the two arch-foes over Tehran's nuclear ambitions. Caldwell said training was taking place in Iran on how to use explosively formed projectiles (EFPs), a particularly lethal roadside bomb that has killed more than 170 U.S. soldiers. U.S.-led forces have launched an operation in Baghdad to curb sectarian violence that threatens to erupt into civil war. Caldwell said that for the third month in a row, civilian casualties had declined in Baghdad but that in the same period there had been an increase in casualties across Iraq. CLERIC CRITICISES MALIKI A row in Washington between U.S. President George W. Bush and the Democratic-controlled Congress over setting a timetable for a U.S. troop withdrawal also spilled over into Iraq. Fiery Shi'ite cleric Moqtada al-Sadr criticised Prime Minister Nuri al-Maliki for saying there was no need for a timetable, saying Maliki was ignoring the demands of Iraqis. The political movement of the anti-American cleric threatened to pull out of the government to press the case. It was not the first time the Sadrists threatened to quit the unity government, but Sadr's comments were a rare criticism of fellow Shi'ite Maliki and might raise questions over his continued support for the two-month-old Baghdad security plan. "What do you (Maliki) say to the millions who crawled to holy Najaf and ... with their voices demanded the exit of the occupiers," Sadr said in a statement, referring to protesters who answered his call for a big anti-American rally in the city last Monday. While Sadr's movement said the turnout was huge, other estimates put the number at tens of thousands. The rally demanded the withdrawal of some 140,000 U.S. troops from Iraq. Bush warned on Tuesday that setting timetables would undermine the Baghdad offensive. Iraq's Shi'ite-led government has had to tread a delicate path in trying to maintain good relations with both fellow Shi'ite Iran and the United States. It says it is working hard to secure the release of the five Iranians held by U.S. forces. Iran, which refused to allow Maliki's plane to fly through its airspace on his way to Japan at the weekend, has said it is not satisfied and warned Baghdad that relations could be hurt. World powers and Iraq's neighbours are due to attend the conference on Iraq in Cairo in the first week of May. "We have reminded Iraqi officials that as long as the Iranian diplomats are not freed, Iran's participation at any conference about Iraq with the presence of America will face a serious problem and obstacle," Abbas Araghchi, a senior Foreign Ministry official, told Iran's hardline Kayhan daily. The meeting is regarded as crucial to stabilising Iraq. (Additional reporting by Dean Yates, Aseel Kami and Ahmed Rasheed in Baghdad and Edmund Blair in Tehran)
