Amid growing dissent in the Baltics, especially Lithuania, in January 1991 Gorbachev demanded that the Lithuanian Supreme Council rescind its pro-independence reforms. Soviet troops occupied several Vilnius buildings and clashed with protesters, 15 of whom were killed. Gorbachev was widely blamed by liberalizers, with Yeltsin calling for his resignation. Gorbachev denied sanctioning the military operation, although some in the military claimed that he had; the truth of the matter was never clearly established. Fearing more civil disturbances, that month Gorbachev banned demonstrations and ordered troops to patrol Soviet cities alongside the police. This further alienated the liberalizers but was not enough to win-over hardliners. Wanting to preserve the Union, in April Gorbachev and the leaders of nine Soviet republics jointly pledged to prepare a treaty that would renew the federation under a new constitution; but six of the republics—Estonia, Latvia, Lithuania, Moldova, Georgia, and Armenia—did not endorse this. A referendum on the issue brought 76.4% in favor of continued federation but the six rebellious republics had not taken part. Negotiations as to what form the new constitution would take took place, again bringing together Gorbachev and Yeltsin in discussion; it was planned to be formally signed in August.