ground force standard medium machine guns. The 12.7mm Browning M2HB heavy machine gun is generally used as a vehicle-mounted machine gun used by motorised infantry. The ground force uses two types of mortar for indirect fire support when heavier artillery may not be appropriate or available. The smallest of these are the 81mm M252, B455 and L16A1 mortars that normally assigned at the infantry company level. At higher echelon, infantry battalions are supported by a section of 120mm M-41D and 2B11 mortars, which are usually employed by motorized units. Fire support for infantry units is mainly provided by towed howitzers, including the lighter 122mm D-30H63 and heavier 155mm FH-70 field howitzers. However, in recent years, Estonia has started to procure increasing numbers of self-propelled artillery vehicles to provide fire support for its increasingly mechanized infantry, reducing the role of towed artillery. Estonia donated at least nine D-30s as well as an unspecified number of FH-70 howitzers to Ukraine as part of its military support to Ukraine's defence against the Russian invasion of 2022. The ground force uses a variety of shoulder fired missiles, recoilless rifles and anti-tank guided missiles to provide infantry and mechanized units with an anti-armor capability. The 82mm B-300 is a reusable man-portable anti-tank shoulder-fired missile system. The 84mm AT4 is an unguided projectile that can destroy armor and bunkers at ranges up to 500 meters. The 90mm C90-CR is a disposable, shoulder-fired and one-man operated grenade launcher. Some motorized units are supported by Pvpj 1110 and M40-A1 recoilless rifles that are mounted on high-mobility utility vehicles. The 115mm MILAN-2 with the night-firing ability and 148mm MAPATS laser-beam riding anti-tank guided missiles are the ground forces' main anti-tank weapon systems. The purchase of the 127mm FGM-148 Javelin fire-and-forget anti-tank missiles will increase the ground forces' anti-armor units capabilities. The 90mm Mistral is an infrared homing surface-to-air missile, which along with the 23mm ZU-23-2 twin-barreled anti-aircraft cannons mounted on trucks make up the backbone of the defense forces' air defense. Vehicles The ground force currently does not operate any main battle tanks although some types were in service of the ground force till the Soviet occupation in 1940. In recent years the Estonian MoD has indicated a need to obtain main battle tanks by 2020 according to the national defense development plan. As 2014, the infantry fighting vehicle CV9035 is the ground force's main battle and frontline troop