Shipping on the Rhine was halted after water levels rose.Officials said the flooding was expected to worsen as flood water swept towards the Danube.Fires continued to rage across a parched Portugal, with weather forecasters warning of "maximum risk" of fire throughout the country. Police arrested four young people, two of them 14 years old, suspected of arson, and recovered a lighter used to start the fires. One of the suspects, an unemployed man, was a former firefighter.The worst blazes destroyed houses outside the central town of Coimbra, home of Portugal's oldest university, where more than 300 firefighters battled to douse flames. Hundreds of towns and villages were cut off yesterday as flooding and heavy rain continued to sweep through Austria, Switzerland and south Germany. In Switzerland two firemen were killed in a mudslide and hundreds of residents in the canton of Lucerne were evacuated from their homes after rivers burst their banks. Three firefighting planes flew in yesterday from Germany, following an appeal over the weekend from Portugal's President Jorge Sampaio for help "to fight this terrible tragedy".The fire moved into Coimbra suburbs after consuming nearby woodland, destroying houses and forcing scores of people to flee.Hundreds of armed forces are mobilised to help some 2,300 firefighters operating nationwide. The floods stopped rail services through the Alps towards Italy and forced major roads to be closed.In Austria, the army was called in yesterday to fortify flood defences. Two people were killed by rain-induced avalanches and several people in an apartment block in the town of Reuthe were injured after flooding caused a gas explosion.

One person died in a rockslide in the Tyrol.In Innsbruck, homes in the town centre were evacuated as the authorities waited for the river Inn to burst its banks.In southern Germany, police said the resort of Garmisch-Partenkirchen was wholly cut off by flooding that had forced the closure of the main Munich to Stuttgart autobahn. But the immunity granted for candidates would not free him from serving his current sentence.. Extreme weather is devastating two regions of Europe, with at least five people reported killed by storms in Austria and Switzerland, while scores of fires rage in Portugal. Let the Kremlin think it is showing strength, in fact it is a display of their weakness and fear."Mr Khodorkovsky, the 42-year-old founder of the Yukos oil company, was sentenced in May to nine years in jail for fraud and tax evasion.

Mr Lebedev was given the same jail term.Mr Khodorkovsky has criticised the Kremlin in a range of articles and interviews, and is said to be considering running in an upcoming parliamentary by-election.Mr Lebedev's lawyers say he is not getting adequate medical treatment.Mr Khodorkovsky said this week he would consider running for a vacant seat in the lower house of parliament in December.The head of the central electoral commission, Alexander Veshnyakov, said Mr Khodorkovsky could register as a candidate before his sentence came into force. "It is obvious that they threw my friend into the isolation cell to avenge me, Mikhail Khodorkovsky, for my articles and interviews. Khodorkovsky has been refusing food and water for several days in the Moscow jail cell he shares with 10 other inmates. In a statement read in part by Khodorkovsky's lawyer Anton Drel on NTV television, the billionaire claimed President Vladimir Putin's Kremlin was behind decisions by prison authorities to transfer Platon Lebedev to isolation and move him to a more crowded cell."On 19 August, my comrade Platon Lebedev was moved to a 32-square-foot isolation cell Platon is seriously ill," the statement said. Jailed Russian oil magnate Mikhail Khodorkovsky is on hunger strike in protest at prison authorities who have moved his business partner into an isolation cell. The Animal Rights Militia claimed responsibility for the incident. It has also deployed thousands of officers policing the regular protests outside the farm.Inspector David Bird, of the force's specialist Environmental Protest Unit, said the announcement would have no impact on the search to find those who had desecrated Mrs Hammond's grave. The offence is punishable by five years in jail.A spokesman for the Department of Trade and Industry said: "The Government is determined to tackle extremists who harass or threaten those involved in vital, life-saving scientific research and is committed to a policy of reducing, refining and replacing the use of animals in research."Professor Tipu Aziz, a consultant neurosurgeon at the Radcliffe Infirmary in Oxford, who uses primates in his research into Parkinson's disease, called the closure as a "tragedy".