BERLIN (Reuters) - Kremlin critic Alexei Navalny should be released immediately, Germany’s Foreign Minister Heiko Maas said on Monday. “Russia is bound by its own constitution and by international obligations to the principle of the rule of law and to the protection of civil rights,” Maas said in a statement. “These principles must, of course, be applied to Alexei Navalny as well. He should be released immediately.” Police detained prominent Kremlin critic Alexei Navalny on arrival in Moscow on Sunday after he flew home to Russia from Germany for the first time since he was poisoned last summer, triggering a political clash with the West.