After the departure of the aid-de-camp, general Lubinski commenced his march, and, though it was practicable for him to reach Ostrolenka by a direct route, yet thinking it possible that Czyzew was not occupied by a very strong force, and that he might profit by the approach of night, he determined to march at once upon the latter place, and to attack the Russian advanced guard there. This bold thought was executed with perfect success. On reaching Czyzew he found two regiments of cavalry encamped, and wholly unprepared for an attack. They had not even an outer-guard upon the road to Nur. He made a charge which threw them into complete disorder, and compelled them to retreat with the loss of a great number in killed and wounded, and four to five hundred prisoners. It was to be regretted that the necessity under which general Lubinski was placed of reaching Ostrolenka as soon as possible, did not permit him to profit farther by these advantages. On the next day, (the 25th) the rear-guard of our main army, consisting of the brigade of general Wengierski, was attacked at mid-day by the Russians, on the side of Zambrowo, near Kleczkowo (20), a village situated at the distance of three leagues from Ostrolenka, on the left bank of the Narew. General Diebitsch, being under the conviction that he had encountered the whole Polish force at Kleczkowo, consolidated his strength there, and determined to come to action, and, by so doing, give time for another corps to advance in the direction of Czyzew, and occupy Ostrolenka, by which movement he trusted that our army would be cut off from Warsaw, and forced to retire to Lomza. The Russian commander, presuming on the celerity of his movements, was so confident of meeting our whole army at this point, that nothing could exceed his surprise on learning that our army had already passed the town, and that it was only the rear-guard which was before him.[61] In order to lose no time, he commenced an immediate attack on the rear-guard thus posted at Kleczkowo. Our general in chief who was then at Troszyn, on hearing the fire of the Russians at Kleczkowo, immediately repaired thither, and profiting by the fine position of that place, which commanded the marshy plain on the side of the enemy, passable only by a dyke, the bridge over which had been demolished by our troops, ordered general Wengierski to sustain himself in that position until night. In vain the Russian cavalry and infantry attempted to pass this dyke. At each approach they were uniformly driven back by a destructive fire of grape from our artillery. In vain were sixteen pieces of their artillery employed to silence this fire; our position was too commanding to be affected by them.