Iraq paused its Tikrit offensive on Monday and officials called for more airstrikes against Islamic State militants, while an officer said Kurdish forces sustained two more chlorine gas attacks by insurgents.

Gen. Aziz Waisi told journalists the insurgents used chlorine twice during a January offensive west of Mosul and once in a December attack on his military police brigade in the Sinjar mountain area. One attack near Mosul, on Jan. 23, was described by Kurdish authorities on Saturday.

Waisi said a number of military police — he did not say how many — were taken to a hospital, where blood tests indicated they had inhaled chlorine gas released by the bombs.