In a phone call to German Chancellor Angela Merkel Tuesday night, President Vladimir Putin warned that by sending troops against pro-Russian separatists, Kiev has brought Ukraine to the verge of civil war. He described the situation as a sharp escalation. The Kremlin reported that both leaders emphasized the importance of the four-way talks on Thursday between Russia, the EU, the US and Ukraine. Pro-Russian separatists have seized buildings in about 10 towns in support of their demand for greater autonomy or referendums on secession to Russia.