LISBON, Portugal (AP) — Soldiers are driving tanker trucks to distribute gas in Portugal as an open-ended truckers' strike over pay enters its second day.

Police officers are also making deliveries as close to 500 of the country's about 3,000 gas stations were reported dry Tuesday.

The government has issued an order allowing the army to be used. It has also enacted a rarely-used legal measure which introduces a punishment of up to two years in prison for strikers who do not carry out a minimum volume of daily gas deliveries stipulated by the government.

The government announced those steps late Monday after deciding that international airports and gas stations in the southern Algarve vacation region, which hosts 1 million tourists in August, were not receiving their stipulated supplies.