The European Union is "gravely concerned" about fighting between government forces and Islamic operatives in Pakistan because of the possibility it may spill over into Afghanistan, EU foreign policy chief Javier Solana said Tuesday. "The EU position is that we are gravely concerned because Pakistan is an important country," Solana said after talks with UN Secretary-General Ban Ki-moon. "Also, because the frontier between Afghanistan and Pakistan is fundamental for peacekeeping operations in Afghanistan, where many European countries have deployed troops," Solana said. Pakistani troops stormed Islamabad's Red Mosque on Tuesday in an attempt to flush out Islamic gunmen said to be holding a number of hostages. The extremists had been trying to impose Taliban-style morality in the capital through a six-month campaign of kidnappings and threats.