US forces step up offensive in Najaf as 50 militia killed

US forces said they killed almost 50 militiamen loyal to the Iraqi Shia cleric Muqtada Sadr in battles in the holy city of Najaf yesterday, as tanks and helicopter gunships pounded the city's vast cemetery.

US forces said they killed almost 50 militiamen loyal to the Iraqi Shia cleric Muqtada Sadr in battles in the holy city of Najaf yesterday, as tanks and helicopter gunships pounded the city's vast cemetery.

American forces captured a brother-in-law and aide of Sadr in Najaf, and there was also fighting inside Baghdad, with US forces claiming they killed nearly 20 militiamen in the Shia slums of the Sadr City district.

Two Russian engineers working on Baghdad's electricity supply were killed yesterday when masked gunmen ambushed a minibus they were in. The Russian company they worked for said it was evacuating all of its 241 staff from Iraq, which could be a serious blow to reconstruction efforts.

The Valley of Peace cemetery in Najaf is where all Iraqi Shia aspire to be buried, near the country's holiest shrine. But in recent weeks the cemetery, which is as big as a small town and believed to be the biggest in the world, has become a battleground between US forces and Sadr's Mehdi Army militia.

American soldiers have tried to advance into Najaf to crush Sadr's uprising, but his militiamen have taken to the narrow alleys of the cemetery, where they can use guerrilla tactics against the Americans, emerging to open fire then disappearing among the tombs.

There has been outcry across the Shia world at the fighting inside the holy city. But US forces appear to be stepping up their offensive. The heaviest fighting was before dawn yesterday. By sunrise, the Americans said they had killed just under 50. There was no confirmation from the Mehdi Army and witnesses spoke only of some 30 wounded.

American soldiers captured Sadr's brother-in-law, Riyadh al-Nouri, at his home in Najaf yesterday. He offered no resistance, said Azhar al-Kinani, of Sadr's office in Najaf. Mr Nouri's capture will be seen as a blow to the Mehdi Army, principally because he is a relative of Sadr. Although he was identified as an aide, he is not believed to be among the most senior officials in his organisation.

There was also fighting between Sadr's followers and US forces in Sadr City slums. There have been on-off clashes in the area for weeks, with US soldiers repeatedly demolishing Sadr's office there, and local residents repeatedly rebuilding it. Sadr draws some of his strongest support in Sadr City, which was renamed in honour of his late father, a Shia spiritual leader murdered by the Saddam regime.

Sadr launched his uprising in April after the US occupation leadership moved against him, closing a newspaper he ran and arresting one of his aides. A warrant for his arrest has been issued in connection with the killing of another Shia cleric in 2003, but the warrant was made public only after Sadr launched his uprising.

The Russian engineers who were killed yesterday were the last group on their way to more secure accommodation at the power station where they worked. An American company, Bechtel, is reconstructing Iraq's electricity network, but the Russians had to be called in because of their specialist expertise in keeping dilapidated power networks up. But Interenergoservis, the Russian company, has already had staff killed or kidnapped. All of its staff who were abducted have since been released unharmed.

But the fact that Russians were targeted despite their government's opposition to the war has unnerved many contractors.