Super-congruences involving trininomial coefficients

The aim of this work is to establish congruences $\left( \operatorname{mod}p^{2}\right) $involvingthetrinomialcoefficients$\binom{np-1}{p-1}{2}$and$\binom{np-1}{\left( p-1\right)/2}{2}$ arising from the expansion of the powers of the polynomial $1+x+x^2\mathrm{.}$ In main results we extend some known congruences involving the binomial coefficients $\left(\genfrac{}{}{0px}{}{np-1}{p-1}\right)$ and $\left(\genfrac{}{}{0px}{}{np-1}{(p-1)\mathrm{/}2}\right)$ and establish congruences link binomial coefficients and harmonic numbers.