The phrase "pockets of territory" is correct and can be used in written English.
It is used to refer to a small area of land within a larger region, typically one that is not under the same control or ownership as the other land in the region. For example, "The country is divided into several pockets of territory, some held by the government and others by rebel forces."
Following a string of territorial losses this year, ISIS fighters have been squeezed into small pockets of territory on the Iraq-Syria border, and towns in Iraq's western Anbar province.
In the east, the army has managed to control only pockets of territory after dark.
Beyond that are pockets of territory which are just too dangerous for anybody.
It is not known what that means for the rest of Kachin State, where the rebels control pockets of territory.
It seems unlikely that in any elections the Baathists -- or autocratic clerics -- would fare well outside small pockets of territory.
The Islamic State holds two pockets of territory in the Euphrates River Valley and along the Syrian border with Iraq.
But one likely location is the pocket of territory that the Northern Alliance controls south of Mazar-i-Sharif.
Rebels managed to seize control of a pocket of territory around Aleppo, but government warplanes and helicopters continue to blast towns they hold from the air.
American forces are massing in the pocket of territory where Kurds who broke with Mr. Hussein in 1991 have maintained years of self-rule under American protection.
In the past few months Mr Masoud's forces, confined to a pocket of territory in the north-east of Afghanistan, have been short of money and arms, facing Taliban fighters convinced they could complete their conquest of the country.
Gen. Atta Mohammad, whose forces took control of two districts just south of Mazar-i-Sharif earlier this week, said that a team of American military personnel was operating in Darra-i-Suf, a town in the pocket of territory his forces control.
