Barack Obama the President of the United States announced on Monday new sanctions against more Russians in an attempt to stop Vladimir Putin the President of Russia from igniting the rebellion more in eastern Ukraine, but said he would hold broader sanctions against the economy of Russia in reserve.

Rebels who are pro-Moscow showed no signs of backing down from their uprising, as they seized public buildings in the east.

The news agency Interfax reported that the mayor of Kharkiv a major city in the east was shot and undergoing emergency surgery. No other details of the shooting were released.

Germany has demanded that Russia act to secure the release of seven military monitors from Europe that are unarmed. Four are from Germany and rebels have held all seven since Friday.

The new sanctions by the U.S. to be outlined in full late Monday, will add additional people and businesses to the list announced in March of figures whose assets were frozen and who have been denied visas for travel into the U.S.

It is also expected that the European Union will add more people to its list who are sanctioned. Twenty-eight ambassadors from EU states met in Belgium and one diplomat from the EU said 15 new names would likely be added to the list.

Washington is also targeting some exports that are high tech, said Obama. However, the measures are not wider sanctions, such as curbing the energy and financial sectors in Russia that would do serious damage to the economy of Russia.

Officials in the U.S. have stated that the updated list would include cronies of Putin in the hope it changed his behavior.

The goal is not to go for Putin personally, but change his calculus with how he is engaging in the current actions taking place in Ukraine.

However, such measures have produced no results and have done nothing to deter Putin. Last month the Russia president overturned years of post Cold War diplomacy to seize and then annex the Crimea Peninsula in Ukraine. He has since placed thousands of his military troops on the border.